Answer:
b. AG, work function=4.74eV
Explanation:
Ultraviolet light starts at the end of the visible light spectrum, where violet light ends:
[tex]\lambda=380 nm =3.8\cdot 10^{-7}m[/tex] (wavelength of lowest-energy ultraviolet light)
So, the lowest energy of ultraviolet light can be found by using the formula
[tex]E=\frac{hc}{\lambda}[/tex]
where
h is the Planck constant
c is the speed of light
Substituting,
[tex]E=\frac{(6.63\cdot 10^{-34} Js)(3\cdot 10^8 m/s)}{3.8\cdot 10^{-7} m}=5.23\cdot 10^{-19}J[/tex]
And keeping in mind that
[tex]1 eV = 1.6\cdot 10^{-19}J[/tex]
This energy converted into electronvolts is
[tex]E=\frac{5.23\cdot 10^{-19} J}{1.6\cdot 10^{-19} J/eV}=3.27 eV[/tex]
The work function of a metal is the minimum energy needed to extract a photoelectron from the surface of the metal. Therefore, the metals that exhibit photoelectric effect are the ones whose work function is larger than the energy we found previously, so:
b. AG, work function=4.74eV
Because for all the other metals, visible light will be enough to extract photoelectrons.
While studying physics at the library late one night, you noticethe image of the desk lamp reflected from the varnished tabletop.When you turn your Polaroid sunglasses sideways, the reflectedimage disappears.
If this occurs when the angle between the incident and reflectedrays is 120^\circ, what is the index ofrefraction of the varnish?
Explanation:
The situation described here is known as polarization by reflection. This was discovered by Scottish physicist David Brewster and then formulated the law that bears his name:
"When a beam of light hits the surface that separates two non-conducting media characterized by different electromagnetic characteristics (electrical permittivity and magnetic permeability), part of it is reflected back to the source medium, and part is transmitted to the second medium."
This polarization happens when the light incides at a specific angle, called the Brewster angle ([tex]\theta_{B}[/tex]), which is given by the following formula (taking into account that generally the magnetic permeabilities of the two media involved do not vary):
[tex]tan\theta_{B}=\frac{n_{2}}{n_{1}}[/tex] (1)
Where [tex]n_{2}[/tex] is the index of refraction of the second medium (the varnish in this case) and [tex]n_{1}=1[/tex] is the index of refraction of the first medium (the air).
Now, if we are told the angle between the incident and reflected rays is [tex]120\°[/tex], this means the incident angle is the half ([tex]60\°[/tex]), which is the Brewster angle in this case.
So, [tex]\theta_{B}=60\°[/tex] (2)
Rewriting (1) with this incident ray angle:
[tex]tan(60\°)=\frac{n_{2}}{1}[/tex] (3)
[tex]n_{2}=tan(60\°)[/tex]
Finally we obtain the index ofrefraction of the varnish:
[tex]n_{2}=1.732[/tex]
The Brewster's angle formula can help determine the index of refraction of a material based on the angle of reflection. In this case, with a 120° angle, the varnish's refractive index would be around 1.732.
When the angle between the incident and reflected rays is 120°, the index of refraction of the varnish can be calculated using the Brewster's angle formula.
For this scenario, if Brewster's angle is 120°, the refractive index of the varnish would be approximately 1.732.
The concept of Brewster's angle relates the angle of incidence and the refractive index of a material for which the reflected ray is entirely polarized, offering a method to determine the index of refraction of the varnish.
What is the shortest distance between two points
Answer: displacement
Explanation:
According to the definition of displacement it is the shortest distance between two points.
Final answer:
The shortest distance between two points is a straight line, which is the displacement in physics. The Pythagorean theorem can be used to calculate this distance in a two-dimensional space. Displacement differs from the total distance traveled as it signifies the most direct path between two points.
Explanation:
The shortest distance between two points is often referred to as a straight line. This concept is not only a geometric truth but also has applications in physics, particularly when discussing displacement and distance traveled.
In a two-dimensional space, such as when navigating a city with a grid layout, the shortest path between two points can be visualized as the hypotenuse of a right triangle.
This forms the basis for utilizing the Pythagorean theorem, which is expressed as a² + b² = c², where a and b are the legs of the triangle and c is the hypotenuse. The theorem helps to quantify the straight-line distance between two points, providing a mathematical model for the physical concept of displacement.
Furthermore, in physics, the term 'displacement' is used to describe this shortest-path scenario between the starting and ending points, which differs from the total distance traveled, which accounts for the actual path taken, regardless of its directness.
Why does atomic radius decrease from left to right?
The atomic radius decreases from left to right across a period due to the increase in nuclear charge, which attracts electrons more strongly and pulls them closer to the nucleus. This leads to a contraction of the electron cloud and a decrease in the atomic radius.
Explanation:The atomic radius decreases from left to right across a period in the periodic table due to the increase in the number of protons in the nucleus. This increase in protons enhances the nuclear charge, which in turn attracts the electrons more strongly, pulling them closer to the nucleus. As a result, the effective nuclear charge experienced by the outermost electrons increases, leading to a decrease in the atomic radius.
As electrons are added to the same principal energy level while moving across a period, the increased positive charge of the nucleus draws these electrons closer. This process causes the electron cloud to contract, and thus, the atomic radius decreases. It's important to note that there are some exceptions and nuances, such as electron-electron repulsions and shielding effects, which can influence this trend to some extent.
Moreover, the largest atoms are found in the lower left corner of the periodic table, while the smallest atoms are located in the upper right corner. This phenomenon is a direct result of the aforementioned periodic trends in atomic radii.
HELP
The distance, A, in the image represents
amplitude
frequency
period
wavelength
Amplitude.
The amplitude A is the maximum elongation of each point of the wave with respect to the central or equilibrium position.
In a sinusoid wave is the maximum distance in the absolute value of the curve measured from the x axis, can be represented as y(t) = A sen (ωx + φ).
Example:
y(t) = 10 sin (2πx), Where the amplitud of the sine wave is A = 10
Answer:
A represents the amplitude of the wave. This measures the sound wave's intensity, or volume. Pls mark brainliest. Have a nice day!
Starting from rest, a disk rotates about its central axis with constant angular acceleration. In 1.00 s, it rotates 21.0 rad. During that time, what are the magnitudes of (a) the angular acceleration and (b) the average angular velocity? (c) What is the instantaneous angular velocity of the disk at the end of the 1.00 s? (d) With the angular acceleration unchanged, through what additional angle (rad) will the disk turn during the next 1.00 s?
With constant angular acceleration [tex]\alpha[/tex], the disk achieves an angular velocity [tex]\omega[/tex] at time [tex]t[/tex] according to
[tex]\omega=\alpha t[/tex]
and angular displacement [tex]\theta[/tex] according to
[tex]\theta=\dfrac12\alpha t^2[/tex]
a. So after 1.00 s, having rotated 21.0 rad, it must have undergone an acceleration of
[tex]21.0\,\mathrm{rad}=\dfrac12\alpha(1.00\,\mathrm s)^2\implies\alpha=42.0\dfrac{\rm rad}{\mathrm s^2}[/tex]
b. Under constant acceleration, the average angular velocity is equivalent to
[tex]\omega_{\rm avg}=\dfrac{\omega_f+\omega_i}2[/tex]
where [tex]\omega_f[/tex] and [tex]\omega_i[/tex] are the final and initial angular velocities, respectively. Then
[tex]\omega_{\rm avg}=\dfrac{\left(42.0\frac{\rm rad}{\mathrm s^2}\right)(1.00\,\mathrm s)}2=42.0\dfrac{\rm rad}{\rm s}[/tex]
c. After 1.00 s, the disk has instantaneous angular velocity
[tex]\omega=\left(42.0\dfrac{\rm rad}{\mathrm s^2}\right)(1.00\,\mathrm s)=42.0\dfrac{\rm rad}{\rm s}[/tex]
d. During the next 1.00 s, the disk will start moving with the angular velocity [tex]\omega_0[/tex] equal to the one found in part (c). Ignoring the 21.0 rad it had rotated in the first 1.00 s interval, the disk will rotate by angle [tex]\theta[/tex] according to
[tex]\theta=\omega_0t+\dfrac12\alpha t^2[/tex]
which would be equal to
[tex]\theta=\left(42.0\dfrac{\rm rad}{\rm s}\right)(1.00\,\mathrm s)+\dfrac12\left(42.0\dfrac{\rm rad}{\mathrm s^2}\right)(1.00\,\mathrm s)^2=63.0\,\mathrm{rad}[/tex]
In 1909 Robert Millikan was the first to find the charge of an electron in his now-famous oil drop experiment. In the experiment tiny oil drops are sprayed into a uniform electric field between a horizontal pair of oppositely charged plates. The drops are observed with a magnifying eyepiece, and the electric field is adjusted so that the upward force q E on some negatively charged oil drops is just sufficient to balance the downward force m g of gravity. Millikan accurately measured the charges on many oil drops and found the values to be whole-number multiples of 1.6 × 10−19 C — the charge of the electron. For this he won the Nobel Prize. If a drop of mass 5.2898 × 10−13 kg remains stationary in an electric field of 6 × 105 N/C, what is the charge on this drop? The acceleration due to gravity is 9.8 m/s 2 . Answer in units of C
Answer:
[tex]8.64\cdot 10^{-18} C[/tex]
Explanation:
There are two forces acting on the oil drop:
- The force of gravity, downward, given by
[tex]F_G = mg[/tex]
where m is the mass of the drop and g is the acceleration due to gravity
- The electric force, upward, given by
[tex]F_E = qE[/tex]
where q is the charge of the oil drop and E is the magnitude of the electric field
The oil drop remains stationary, so the two forces are balanced:
[tex]F_G = F_E\\mg = qE[/tex]
where
[tex]m=5.2898\cdot 10^{-13}kg\\E=6\cdot 10^5 N/C\\g = 9.8 m/s^2[/tex]
Substituting into the previous equation and solving for q, we find the charge of the oil drop:
[tex]q=\frac{mg}{E}=\frac{(5.2898\cdot 10^{-13} kg)(9.8 m/s^2)}{6\cdot 10^5 N/C}=8.64\cdot 10^{-18} C[/tex]
The charge of a stationary oil drop can be calculated by balancing gravitational force with electric force. In this case, the calculated charge is approximately -1.37 x 10-18 C, indicating about 9 excess electrons on the oil drop.
Explanation:
In Robert A. Millikan's famous oil drop experiment, we balance the downward gravitational force with an upward electric force to determine the charge of an electron. In this case, with the oil drop being stationary, it means that these two forces are equal. Therefore, we can say that the upward force (qE) is equal to the downward force (mg).
By rearranging this equation for q (charge), we get q = mg / E. Substituting the given values, mass m = 5.2898 × 10-13 kg, acceleration due to gravity g = 9.8 m/s2, and electric field E = 6 × 105 N/C, into this formula, we get q = (5.2898 × 10-13 kg * 9.8 m/s2) / 6 × 105 N/C.
This gives us the charge q = -1.37 x 10-18 C. Finally, from Millikan's oil drop experiment, we know the quantized charge of an electron is -1.6 x 10-19 C, therefore, it indicates that there are approximately 9 excess electrons on the oil drop.
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Refraction occurs when light passing from one medium to another. True or False
Answer: True
Refraction is a phenomenon in which the light bends or changes its direction (and changes the speed of propagation, as well) when passing through a medium with a refractive index [tex]n[/tex] different from the other medium.
Where the Refractive index is a number that describes how fast light propagates through a medium or material:
[tex]n=\frac{c}{v}[/tex]
Being [tex]n[/tex] a relation between the speed of light in vacuum [tex]c[/tex] and its speed in the other medium [tex]v[/tex] .
It is important to note that in this process, the wavelength may be modified because it depends on the medium, however, the refracted ray of light does not change its frequency.
How can solar energy be used to produce electricity
Answer:
Explanation:
Electricity is generated from solar energy predominantly by the use of photovoltaic cells.
The sun is the ultimate source of energy for all life and the bulk of the solar system at large.
Energy from the sun is used for various life processes and other abiotic uses.
In order to harness the sun's energy to produce electricity, a photovoltaic cell is required. These cells are often used in making solar panels which are available in most places today.
Electricity is produced by the movement of electrons within a cell or a body. In a photovolatic cell, the radiation from the sun causes chemical reactions to occur on the surface of these materials. The reaction is such in which electrons are produced. The movement of electrons in these cells results in the generation of electricity.
In some other cases, sunlight can be concentrated for heating water to produce steam. Steam can be used to drive turbines to produce electricity too.
How deep in the ocean is the wreckage of the titanic?
Answer:
12,500 feet
Explanation:
A constant voltage is applied across a circuit. If the resistance in the circuit is doubled, what is the effect on the power dissipated by the circuit?
a.The power dissipated is quadrupled
b.The power dissipated is reduced by a factor of 2.
c.The power dissipated is reduced by a factor of 4
d. The power dissipated is doubled.
e. The power dissipated remains constant.
Answer:
b.The power dissipated is reduced by a factor of 2.
Explanation:
The power dissipated in the circuit is given by
[tex]P=\frac{V^2}{R}[/tex]
where
V is the voltage
R is the resistance
In this problem:
- The voltage V is kept constant
- The resistance is doubled, so R' = 2R
Therefore, the new power dissipated is
[tex]P'=\frac{V^2}{R'}=\frac{V^2}{2R}=\frac{1}{2}\frac{V^2}{R}=\frac{1}{2}P[/tex]
so, the power dissipated is reduced by a factor of 2.
Final answer:
When resistance is doubled and voltage is constant, the power dissipated by the circuit is halved. The power is proportional to the inverse of resistance, so doubling resistance reduces power by a factor of 2.
Explanation:
When the resistance in a circuit is doubled while keeping the voltage constant, the current in the circuit according to Ohm's Law (V = IR) will be halved, because I = V/R. The power dissipated by the circuit can be calculated using the formula P = V2/R. If the resistance is doubled, the new power dissipated becomes Pnew = V2/(2R), which is half the original power. Since the original power is Porig = V2/R, by doubling the resistance, the power is effectively reduced by a factor of 2, not 4.
Thus, the correct answer is: b. The power dissipated is reduced by a factor of 2.
________ are more likely to be found near rural communities due to the large requirement for space.
Military bases
Farms
Domed stadiums
Coal mines
Complex highway interchanges
Military bases and Farms, Domed stadiums are more likely to be found near rural communities due to the large requirement for space.
What is Rural Communities?
A rural area is an expanse of open ground with few houses or other structures and few inhabitants. The population density in a rural location is very low.
A rural area is an expanse of open ground with few houses or other structures and few inhabitants. The population density in rural areas is quite low. Numerous individuals reside in urban or suburban areas. Their residences and places of business are situated close together.
Most rural communities' main industry is agriculture. On farms or ranches, the majority of people reside or work.
Therefore, Military bases and Farms, Domed stadiums are more likely to be found near rural communities due to the large requirement for space.
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A neutral object develops an electric charge when it either gains or loses electrons
True or false ?
Answer:
True
Explanation:
A neutral object is an object whose net charge is zero, so the sum of the positive charges is equal to the sum of negative charges:
[tex]Q=Q_{pos}+Q_{neg}=0\\Q_{pos} = -Q_{neg}[/tex]
If the neutral object develops an electric charge (= different from zero), it means that this balance has changed. In particular, usually electric charge is carried by electrons (negative charges), so the object has either gained or lost electrons.
In particular:
- if the object has gained electrons, it has became negatively charged
- If the object has lost electrons, it has became positively charged
What are the four types of macromolecules
Hello There!
The 4 types of macromolecules are
NUCLEIC ACIDS
PROTEINS
LIPIDS
CARBOHYDRATES
Answer:
1 2 3 4
Explanation:
proton with an initial speed of 800000 m/s is brought to rest by an electric field.
Part A- Did the proton move into a region of higher potential or lower potential?
Part B - What was the potential difference that stopped the proton?
ΔU = ________V
Part C - What was the initial kinetic energy of the proton, in electron volts?
Ki =_________eV
Best Answer
A) Into a region of higher potential
Explanation:
Let's remind that:
- Like charges repel each other
- Unlike charges attract each other
Here we have a proton, which is a positive charge, which is brought to rest by an electric field. This means that the electric field has slowed down the proton: so, the force exerted by the electric field on the proton was opposite to the direction of motion of the proton. But the lines of an electric field go from points at higher potential to points at lower potential - this means that the proton was actually moving towards a point at higher potential. (for example, it was moving towards another positive charge source of the field, so the potential increases as the proton approaches the source charge).
B) 3,338 V
The initial kinetic energy of the proton is given by:
[tex]K_i = \frac{1}{2}mv^2[/tex]
where
[tex]m=1.67\cdot 10^{-27} kg[/tex] is the proton mass
[tex]v=800,000 m/s=8\cdot 10^5 m/s[/tex] is the initial speed
Substituting,
[tex]K_i = \frac{1}{2}(1.67\cdot 10^{-27}kg)(8\cdot 10^5 m/s)^2=5.34\cdot 10^{-16}J[/tex]
When the proton is brought to rest, all this energy is converted into electric potential energy, given by
[tex]\Delta U = q \Delta V[/tex]
where
[tex]q=1.6\cdot 10^{-19} C[/tex] is the proton charge
[tex]\Delta V[/tex] is the potential difference
Since [tex]\Delta U = K_i[/tex], we can solve to find the potential difference:
[tex]\Delta V=\frac{K_i}{q}=\frac{5.34\cdot 10^{-16} J}{1.6\cdot 10^{-19} C}=3,338 V[/tex]
C) 3,338 eV
We already found the initial kinetic energy of the proton in part B), and it is given by
[tex]K_i =5.34\cdot 10^{-16}J[/tex]
Now we want to convert it into electron volts; keeping in mind the conversion factor between eV and Joules,
[tex]1 eV = 1.6\cdot 10^{-19}J[/tex]
we find:
[tex]K_i = \frac{5.34 \cdot 10^{-16} J}{1.6\cdot 10^{-19} J}=3,338 eV[/tex]
The proton moved into a region of higher potential. The potential difference that brought it to rest and its initial kinetic energy can be calculated using formulas and given values.
Explanation:Part A: The proton moved into a region of higher potential. This is because the electric field does work on the proton to bring it to a stop, which indicates that the proton moved against the direction of the electric field and hence into a region of higher potential.
Part B: The potential difference that stopped the proton can be calculated using the formula ΔU = ΔK/e, where ΔK is the change in kinetic energy and e is the charge of the proton. Given that the initial speed of the proton is 800000 m/s (which implies a kinetic energy of ½ mv^2), and knowing that the charge of a proton is 1.6 x 10^-19 C, you can solve this equation to find ΔU.
Part C: The initial kinetic energy of the proton can be calculated using the formula K = ½ mv^2. Converting this to electron volts (eV) involves dividing by the charge of an electron (e), which is also 1.6 x 10^-19 C.
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Which of the following selections completes the following nuclear reaction?
Answer:
n (a neutron)
Explanation:
For a chemical element:
- The lower subscript indicates the atomic number (the number of protons)
- The upper subscript indicates the mass number (the sum of protons and neutrons in the nucleus)
In the reaction described in the problem, we see that a gamma photon hits a nucleus of Calcium-40, which has
Z = 20 (20 protons)
A = 40 (40 protons+neutrons)
Which means that the number of neutrons is n = A - Z = 40 - 20 = 20
After the reaction, we have a nucleus of Calcium-39, which has
Z = 20 (20 protons)
A = 39 (39 protons+neutrons)
Which means that the number of neutrons is n = A - Z = 40 - 39 = 19
So, the nucleus has lost 1 neutron, which is the particle missing in the reaction.
Two identical satellites orbit the earth in stable orbits. One satellite orbits with a speed v at a distance r from the center of the earth. The second satellite travels at a speed that is less than v. At what distance from the center of the earth does the second satellite orbit?
Answer:
The second satellite will orbit at a larger distance
Explanation:
A satellite orbits the Earth due to its gravitational attraction to the Earth, which is equal to the centripetal force, so we can write
[tex]G\frac{Mm}{r^2}=m\frac{v^2}{r}[/tex]
where
G is the gravitational constant
M is the Earth's mass
m is the satellite's mass
r is the distance of the satellite from Earth's center
v is the speed of the satellite
We can rewrite the formula as
[tex]r=\frac{GM}{v^2}[/tex]
so we see that the distance of the satellite from the center of the Earth is inversely proportional to the square of the distance. This means that the second satellite, which travels at a lower speed, will have a larger distance from the centre of the Earth.
A satellite orbiting at a lesser speed than another identical satellite orbits at a greater distance from the center of the earth based on principles of orbital dynamics and Kepler's Second Law.
Explanation:The distance at which the second satellite orbits the earth, with a speed less than v, is greater than r. This is based on principles of orbital dynamics, which show a relationship between orbital speed and the distance from the center of the object being orbited. Looking at the gravitational force that supplies the centripetal acceleration for an orbiting object, we can see that as speed decreases, the gravitational force also decreases, meaning the object must be further from the center of gravity.
Take into consideration Kepler's Second Law, in that the satellite travels an equal area within equal times. If we consider two satellites orbiting, the one with a lesser speed will take a greater time to cover the same area, hence, it will be at a greater distance from the earth's center.
These observations are true for stable, circular orbits. Real world conditions might vary due to additional influences such as atmospheric drag, oblateness of the earth, and gravitational perturbations from the sun and moon.
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A runner moves 2.88 m/s north. She accelerates at 0.350 m/s^2 at a -52.0 angle. At the point in the motion where she is running directly east, what is Δx?
Answer:
Δx = 11.7 and Δy = 15
The question requires the use of kinematics and vector decomposition to calculate the horizontal displacement of a runner when she changes direction from the north to the east due to acceleration at a given angle.
The student is asking about the projection motion of a runner moving north, who accelerates at an angle. The question focuses on calculating the horizontal displacement (denoted as Δx) when the runner is running directly east. To solve this, one would have to break down the acceleration vector into its northward and eastward components and then use kinematic equations to determine the eastward displacement from the point of initial velocity to the point where the northward velocity component reaches zero and the runner is moving directly east.
Is the distance traveled during a specific unit of time.
Answer:
Speed is the distance traveled during a specific unit of time.
Answer:
speed
Explanation:
edge 2021
A submarine can withstand an external pressure of 63 atm before collapsing. If seawater has a density of 1027 kg/m^3 how deep can the sub dive?
Answer:
623.8 m
Explanation:
Which law states that each planet revolves so that an imaginary line connecting it to the sun sweeps over equal areas in equal time intervals?
Kepler’s Laws are three mathematic laws to describe the movement of the planets around the Sun, but it can be generalized for the movement of any body orbiting a bigger one, for example, The Moon orbiting the Earth.
These laws were formulated by the astronomer Johannes Kepler from observations made by the Danish astronomer Tycho Brahe of the orbit of Mars.
Now, according to the Second Kepler’s Law of Planetary motion:
In equal times, the areas swept by the planet in its orbit around the Sun are equal.
For this to be possible, the speed of the planet must vary. Hence, the planet will move rapidly near the Sun (perihelion) and move slowly when it is away from the Sun (aphelion).
What effect does friction have on a roller coaster
Hello There!
Let's first talk about "What Is Friction"
Friction is a force that pulls when two object touch each-other. Friction happens because the molecules on one surface interlock with the molecules on another surface.
Now, let's get back to our original question "What Effect Does Friction Have On A Roller Coaster"
On a roller coaster, friction is a force that opposes motion and significantly slows the cars as they move on the track.
Which of these stars has the coolest surface temperature?A. A starB. F starC. G starD. K star
Answer:
D. K star
Explanation:
Stars are classified into different groups according to their peak wavelength and their surface temperature.
In particular, we have the following group of stars, which correspond to the following surface temperatures:
Group O - Temperature > 25,000 K
Group B - Temperature 11,000 - 25,000 K
Group A - Temperature 7,500 - 11,000 K
Group F - Temperature 6,000 - 7,500 K
Group G - Temperature 5,000 - 6,000 K
Group K - Temperature 3,500 - 5,000 K
Group M - Temperature < 3,500 K
So among the options given, the star with the coolest surface temperature is star in group K.
The coolest surface temperature among the options is a K star. Ait depends on the surface temperature. The correct option is option (D).
Stars are categorized into different spectral classes based on their surface temperature.
The spectral classes are labeled with letters, starting from the hottest to the coolest: O, B, A, F, G, K, and M. So, a K star has a cooler surface temperature compared to an F star, a G star, and an A star.
Therefore, the correct option is option (D) K star has the coolest temperature.
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What lowers the freezing point of water?
Answer:
It cannot be changed
Explanation:
The freezing point of water cannot be changed; it stays the same.
The amount of space an object takes up is its
Volume.
Hope this helps.
r3t40
Average speed is the total distance divided by the
Time
Explanation:The average speed of an object that is moving is defined as the distance traveled divided by the time of travel. You can measure the distance with a ruler and the time with a stopwatch. This can be expressed as the following formula:
[tex]v=\frac{\Delta x}{\Delta t}[/tex]
For instance, if an object travels a distance [tex]\Delta x=100m[/tex] in 4 seconds, the the average speed is:
[tex]v=\frac{100m}{4s} \\ \\ \therefore \boxed{v=25m/s}[/tex]
Average speed is calculated by dividing the total distance traveled by the elapsed time, represented as D / Δt, where D is distance and Δt is the time interval. It is a scalar quantity, indicating the average rate of travel without regard to direction.
Explanation:The question asks, "Average speed is the total distance divided by the?" The answer is elapsed time. Average speed is a fundamental concept in physics that represents the average rate at which distance was traversed over a period of time. It is calculated by dividing the total distance traveled by the total time taken for the journey. Unlike average velocity, which is a vector quantity and considers direction, average speed is a scalar quantity, meaning it only considers magnitude and has no direction associated with it. To calculate average speed (ϕavg), the formula used is: vavg = D / Δt, where D represents the distance traveled and Δt represents the time interval.
For example, if a person travels 100 kilometers over 2 hours, their average speed would be calculated as 100 km divided by 2 hours, resulting in an average speed of 50 km/h. This calculation indicates that, on average, the person covered 50 kilometers for each hour of travel. It's critical to differentiate between average speed and average velocity because the latter takes into account the travel direction, whereas the former does not. Understanding average speed is crucial for solving a plethora of problems in physics, particularly those related to motion and dynamics.
When a second identical bulb is added in series to a circuit with a single bulb, the resistance of the circuit
Answer:
Will double
Explanation:
The total resistance of a circuit with n resistors in series is equal to the sum of the individual resistances:
[tex]R_T = R_1 + R_2 + ... + R_n[/tex]
In this problem, we have a circuit with initially one light bulb of resistance R, so the total resistance of the circuit is:
[tex]R_T = R[/tex]
Later, a second identical bulb (so, same resistance R) is added in series to the circuit; so applying the previous formula, we see that the new total resistance is
[tex]R_T = R + R = 2 R[/tex]
So, the resistance has doubled.
What causes convection currents to occur?
Answer:
Convection currents are caused by an uneven temperature within something.
For example, within the earth, Convection currents occur when a reservoir of fluid is heated at the bottom, and allowed to cool at the top.. Heat causes the fluid to expand, decreasing its density. If there is cooler material on top, it will be more compact and therefore, will sink to the bottom. The heated material will rise to the top.
Hydrogen-2 and Hydrogen-3 fuse to form Helium-4 and a neutron. How much energy is released in this nuclear reaction?
Final answer:
In a nuclear fusion reaction, when hydrogen-2 and hydrogen-3 combine to form helium-4 and a neutron, a certain amount of energy is released. The exact amount of energy released can be calculated using the equation E = mc^2, where E is the energy, m is the change in mass, and c is the speed of light.
Explanation:
In a nuclear fusion reaction, when hydrogen-2 (deuterium) and hydrogen-3 (tritium) combine to form helium-4 and a neutron, a certain amount of energy is released. The exact amount of energy released can be calculated using the equation E = mc2, where E is the energy, m is the change in mass, and c is the speed of light.
Based on the given information, we can calculate the change in mass by subtracting the mass of the reactants from the mass of the products. The mass of deuterium (hydrogen-2) is 2 grams, the mass of tritium (hydrogen-3) is 3 grams, the mass of helium-4 is 4 grams, and the mass of a neutron is negligible. Therefore, the change in mass is 2 grams + 3 grams - 4 grams = 1 gram.
Using the equation E = mc2, where c is the speed of light (approximately 3 x 108 m/s), we can calculate the energy released:
E = (1 gram) x (3 x 108 m/s)2 = 9 x 1016 joules
1).which of the following describes the interaction between a south pole and a north pole of a magnet
a) attract
b) repel
c) stay unchanged
d) it depends
2). which of the following producing a magnetic field
a) motion of electrons
b) pair of atoms
c) magnetic area
d) static charges
1) a) attract
The magnetic force between two magnetic poles is attractive for two unlike poles and repulsive for two like poles. Therefore we have:
1- For two north poles, the force between them is repulsive
2- For two south poles, the force between them is repulsive
3- For a north pole and a south pole, the force between them is attractive
In this problem, we are in the situation described in 3), so the force between the poles is attractive.
2) a) motion of electrons
While electric fields are produced by static electric charges, magnetic fields are produced by charges in motion (currents). In particular, a current in a wire (where a current is simply the motion of electrons inside the wire) produces a magnetic field whose intensity is
[tex]B=\frac{\mu_0 I}{2 \pi r}[/tex]
where
I is the current in the wire
r is the radial distance from the wire
And the direction of the field lines are such that the field form concentric circles around the wire.
Final answer:
A south pole and a north pole of a magnet will attract each other, and a magnetic field is mainly produced by the motion of electrons or the presence of an electric current.
Explanation:
When considering the interaction of magnetic poles, opposite poles indeed attract each other according to magnetic field principles. Specifically, a south pole and a north pole will experience attraction because the magnetic field lines become denser between them, pulling the magnets together. Therefore, the correct answer to the first part of the question is (a) attract.
Regarding what produces a magnetic field, one of the principal sources is the motion of electrons or an electric current. This relationship is observed in electromagnets, where a current flowing through wires creates a surrounding magnetic field. Consequently, the correct answer to the second part of the question is (a) motion of electrons.
At a distance of 0.75 meters from its center, a Van der Graff generator interacts as if it were a point charge, with that charge concentrated at its center. A test charge at that distance experiences an electric field of 4.5 × 10^5 newtons/coulomb. What is the magnitude of charge on this Van der Graff generator?
A. 1.7 × 10^-7 coulombs
B. 2.8 × 10^-7 coulombs
C. 3.0 × 10^-7 coulombs
D. 8.5 × 10^-7 coulombs
Answer: B
i tried putting explanation but its not working
Answer:
B. [tex]2.8 \times 10^{-5} C[/tex]
Explanation:
As we know that the electric field due to Van de graff generator is same as that of a point charge
so it is given by
[tex]E = \frac{kQ}{r^2}[/tex]
here we know that
[tex]E = 4.5 \times 10^5 N/c[/tex]
also we know that
[tex]r = 0.75 m[/tex]
now from above formula we have
[tex]4.5 \times 10^5 = \frac{(9\times 10^9)(Q)}{(0.75)^2}[/tex]
here we will have
[tex]Q = 2.8 \times 10^{-5} C[/tex]