A train travels 50 kilometers in 4 hours, and then 74 kilometers in 2 hours. What is its average speed?

Ernest Rutherford was a British physicist and chemist of New Zealand origin, who conducted a series of experiments together with Hans Geiger and Ernest Marsden; where the result led him to propose a new atomic model.

It should be noted that at that time, the "accepted" atomic model was Thomson's raisin pudding atomic model (electrons with negative charge immersed an the atom of positive charge that counteracted the negative charge of the electrons, like raisings embedded in a pudding), who discovered the electron and formerly was a professor of Rutherford.  

Now, the experiment conducted under the direction of Ruherford at the laboratories of the University of Manchester during the year 1911; was for the purpose of corroborating Thomson's atomic model. To achieve this, a thin metal sheet was bombarded with alpha particles (nuclei of helium gas).

The idea was that these alpha particles, having positive electric charge, were attracted by the atom's negative charges and repelled by the positive charges, and it was expected that they would pass through the thin sheet without hardly deviating. Then, to observe the crash site of the particle, a phosphorescent screen was placed behind and on the sides of the metal sheet.

For according to Thomson's atomic model the positive and negative charges were evenly distributed, the sphere (the atom) had to be electrically neutral, and the alpha particles would pass through the sheet without deviating.

However, the results were surprising:

As expected, most of the particles went through the sheet without deviating.

That is:

These facts could not be explained by Thomson's atomic model, so Rutherford developed another, suggesting that:

This new model could explain the proven fact in his experiments that some particles bounced in the direction opposite to the incident particles, because the electrical charge of this nucleus was positive, equal to the electrical charge of the alpha particles.

This is how Rutherford proposed a new atomic model and discovered the existence of the nucleus. However, this was not the definitive model, because on 1913 it was replaced by Bohr's.

Answer:

To your left

Explanation:

The direction of the force exerted on charged particle due to a magnetic field is given by the right-hand-rule, where:

- The index finger indicates the direction of motion of the electron

- the middle finger gives the direction of the magnetic field

- the thumb gives the direction of the force if the particle is positively charged - otherwise, the direction is reversed

in this case, we have an electron (so, a negatively charged particle):

- The direction of motion (index finger) is horizontal, toward you

- The electron begins to curve upward as it enters the field, so this means that the force exerted on the electrons is upward --> the thumb must point downward (because the electron is negatively charged)

- The index finger gives us the direction of the magnetic field: therefore, to your left.

The correct answer is B)

Final answer:

To double the kinetic energy of a gas molecule, the momentum must be increased by a factor of square root of 2 (B) √2.

Explanation:

If you want to double the kinetic energy of a gas molecule, by what factor must you increase its momentum, the answer is B) √2. Kinetic energy (KE) is given by the equation KE = ½mv², where m is the mass and v is the velocity of the molecule. Since momentum (p) is the product of mass and velocity (p = mv), we can express kinetic energy in terms of momentum as KE = p² / (2m).

Therefore, to double the kinetic energy (2KE), the equation becomes 2(½mv²) = mv², which implies that the new momentum (p') squared would be twice the original momentum squared (2p²). Taking the square root on both sides results in p' = p√2, so the momentum must be increased by a factor of the square root of 2 to double the kinetic energy of the molecule.

Explanation:

1D motion is motion in only one direction.  To put it simply, it's motion along a line.  For example, a train on a straight track has 1D motion.

2D motion is motion in two directions.  A good example of this is a projectile launched at an angle.  It has both vertical motion and horizontal motion.

One dimensional motion is restricted to just a line. Thing about an object that can only travel on the x-axis. It's displacement, velocity and acceleration can be defined by just single numbers. The sign of that number can indicate the direction since there are only two directions.

On the other hand, two dimensional motion can happen on a plane. Think about an object that can travel anywhere on a Cartesian plane (normal graphing paper with x-axis and y-axis). This object's displacement, velocity and acceleration need to defined by two numbers and is done so usually in vectors. For example the position can be (3, 5).

Answer:

1.25 focal lengths

Explanation:

The lens equation states that:

[tex]\frac{1}{f}=\frac{1}{p}+\frac{1}{q}[/tex]

where

f is the focal length

p is the object distance

q is the image distance

In this problem, the image is 4 times as far from the lens as is the object: this means that

[tex]q=4p[/tex]

If we substitute this into the lens equation and we rearrange it, we get

[tex]\frac{1}{f}=\frac{1}{p}+\frac{1}{4p}=\frac{4+1}{4p}=\frac{5}{4p}\\p=\frac{5}{4}f=1.25 f[/tex]

so, the object distance measured in focal lengths is

1.25 focal lenghts

Answer:

39.05 pounds at [tex]60.19^{\circ}[/tex]

Explanation:

To find the resultant force, we need to decompose each vector along the x- and y- directions. Let's do it:

Vector 1:

[tex]A_x = 25 \cdot cos 10^{\circ}=24.62[/tex]

[tex]A_y = 25 \cdot sin 10^{\circ}=4.34[/tex]

Vector 2:

[tex]B_x = 30 \cdot cos 100^{\circ}=-5.21[/tex]

[tex]B_y = 30 \cdot sin 100^{\circ}=29.54[/tex]

Resultant components:

[tex]R_x = A_x + B_x =24.62+(-5.21)=19.41[/tex]

[tex]R_y = A_y + B_y = 4.34+29.54 =33.88[/tex]

So the magnitude of the resultant is

[tex]R=\sqrt{R_x^2+R_y^2}=\sqrt{(19.41)^2+(33.88)^2}=39.05[/tex]

And the direction is

[tex]\theta=tan^{-1}(\frac{R_y}{R_x})=tan^{-1}(\frac{33.88}{19.41})=60.19^{\circ}[/tex]

The resultant force is found by summing the horizontal and vertical components of the two forces and then calculating the magnitude and direction of the resultant vector using the Pythagorean theorem and inverse tangent function respectively.

We can calculate the resultant force by breaking down each force into its horizontal and vertical components, summing these components and then calculating the magnitude and direction of the resultant force by applying principles of trigonometry and vector addition.

The first force of 25 pounds can be broken down into its horizontal and vertical components as follows: the horizontal component will be 25*cos(10°) and the vertical component will be 25*sin(10°).

Similarly, the second force of 30 pounds acts at an angle of 100°. Its components will be: the horizontal component as 30*cos(100°), and the vertical component as 30*sin(100°).

Now, the resultant force will have a horizontal component equal to the sum of the horizontal components of the two forces, and a vertical component equal to the sum of the vertical components of the two forces. Therefore, the horizontal and vertical components of the resultant force can be calculated as the sum of the respective components of the individual forces.

The magnitude of the resultant force can then be found by using the Pythagorean theorem, i.e., the square root of the sum of the squares of the horizontal and vertical components of the resultant force. The direction of the resultant force can be found using the inverse tangent function (atan or tan⁻¹) applied to the ratio of the vertical component to the horizontal component of the resultant force.

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i think it’s asking for ultraviolet

Answer:

Ultraviolet Light

Explanation:

Answer:

Average emf in the coil: 0.0672 V.

Explanation:

Convert all units to standard SI units.

Consider Faraday's Law of Induction:

[tex]\displaystyle \begin{aligned}\epsilon &= \text{Rate of change in}\;(N\cdot \phi)\\&=\text{Rate of change in}\; (N \cdot (B\cdot A\cdot \cos{\theta}))\end{aligned}[/tex]

where

The coil is circular with a radius of [tex]2.41\times 10^{-2}\;\text{m}[/tex]. As a result,

[tex]A = \pi\cdot r^{2} = \pi\times (2.41\times 10^{-2})^{2} = 1.82467\times 10^{-3}\;\text{m}^{2}[/tex].

Neither [tex]N[/tex] nor [tex]A[/tex] changes in this 0.115 seconds. As a result, the average rate of change in [tex]N\cdot B\cdot A[/tex] is the same as [tex]N\cdot A[/tex] times the average rate of change in [tex]B[/tex].

[tex]\displaystyle \begin{aligned}\text{Average}\;\epsilon &= \text{Average Rate of Change in}\; (N\cdot (B\cdot A\cdot \cos{\theta}))\\&=\text{Average Rate of Change in}\; (N\cdot B\cdot A) \\&= (N\cdot A)\cdot \text{Average Rate of Change in}\;B\\&= 107\times 1.82467\times 10^{-3}\times \frac{91.7\times 10^{-3}- 52.1\times 10^{-3}}{0.115}\\ &=0.0672\;\text{V}\end{aligned}[/tex].

All numbers in the question come with three sig. fig. Keep more sig. fig. than that in the calculation but round the final answer to three sig. fig.

The magnitude of the average emf, in millivolts, which is induced in the coil during this time interval is approximately 37.93 mV.

To find the magnitude of the average emf induced in a coil when the magnetic field strength changes, we use Faraday's law of electromagnetic induction. The formula given is:

EMF = N x (\(∆B/\u2206t\)) x A

Where:

First, calculate the area of the coil:

A = \(\pi r² \) = \(\pi \times (0.0241)²\) = \(\pi \times 0.00058081 m²\)

Then, calculating the EMF:
EMF = 107 x (39.6 \times 10⁻³ T / 0.115 s) x (\(\pi \times 0.00058081 m²\))

Upon calculation, you find that the average induced emf is approximately 37.93 millivolts (mV).

Answer:

The force on the faster cart is 3 times the force on the slower cart

Explanation:

The relationship between force exerted on each cart (F), mass of the cart (m) and acceleration (a) is given by Newton's second law:

[tex]F=ma[/tex]

For cart A, we have

[tex]F_A = m a_A[/tex] (1)

For cart B, we have

[tex]F_B = m a_B[/tex] (2)

the problem says that the acceleration of one cart is 3 times the acceleration of the other one, so

[tex]a_B = 3 a_A[/tex]

Substituting into eq.(2):

[tex]F_B = m(3 a_A)=3 (m a_A)[/tex]

So, if we divide (2) by (1), we find the ratio between the two forces:

[tex]\frac{F_B}{F_A}=3[/tex]

so, the force on cart B is 3 times larger the force on cart A.

The car traveled at an average speed of 20 mi/h. Option C

The car will travel at an average speed of 20 mi/h, this is so,  because the average speed is calculated as the total distance traveled divided by the total time taken.

In this case, the car traveled a distance of 8 miles in 24 minutes (which is equivalent to 0.4 hours), so the average speed is 8 miles / 0.4 hours = 20 mi/h.

Options A and B mention acceleration, but there is no information provided to calculate acceleration in this scenario.

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The farthest major planet from the sun is Neptune

Answer:

Option B is ur answer

Answer:

The answer is D

Explanation:

Formed where mantle erupts through crust

Answer:

The Hawaiian Islands were formed where mantle erupts through crust.

Explanation:

All the Hawaiian Islands were formed by the action of volcanoes that arose from the bottom of the sea, from a source of magma (hot spot).

Hawaii's hot spot theory holds that the tectonic plate under the Pacific moves, while the hot spot stands still, creating new volcanoes. For this reason, the volcanoes of the southern half of the island of Hawaii remain active today.

The oldest islands have inactive volcanoes, but in the newest ones volcanoes still active. The island of Hawaii has five volcanoes, and one of them is one of the most active in the world, the Kīlauea.

Answer:

A transformer.

Explanation:

A transformer is a device that involves magnetically coupled coils isolated from one to another but wound on the same magnetic core. A variable current in time in a coil establishes in the magnetic core a flux also variable in time, this flow is linked to the other coil and induces in it an electromotive force (voltage) variable in time.

Answer: C. a transformer.

For USATestprep.

Answer:

3 seconds

Explanation:

Since h(t) represents the height and t represents the time, we can set the equation equal to 150 to find t.

-16t^2+96t+6=150

Subtract 150 from both sides to set the equation equal to 0, to find the solutions.

-16t^2+96t-144=0

Factor out -16, because all of the terms are divisible by it.

-16(t^2+6t+9)=0

Now we can focus on the terms inside the parenthesis and factor it again.

t^2-6t+9=0

We need to find two value that can be multiplied to get 9 and added to get -6.

-3 and -3 works.

Thus, we get (x-3)(x-3).

Now solve for 0.

x-3=0

x=3

The object reaches its maximum height after 3 seconds.

Answer:

3 seconds

Explanation:

Answer:

D. near an ocean coastline

Explanation:

The magnetic needle of a compass can be deviated by the magnetic field that the ocean has, this is important to remember because eventhough it´s not a big difference but it is significant enough to keep it in mind. Ocean can attract the magnetic needle of the compass and create a deviation on it.

Resonance is a phenomenon that occurs when a body capable of vibrating is subjected to the action of a periodic force, whose frequency of vibration approaches the characteristic frequency of vibration (called resonance frequence) of said body. This is due a relatively small force applied in a repeated form, causing the amplitude of the oscillating system to become very large.

In other words, for the specific case of sound waves, this phenomenon occurs when the frequency of the  wave that is external to the system or body coincides with the resonance frequency (characteristic frequency that reaches the maximum degree of oscillation) of this system or body.

In these circumstances the body vibrates, progressively increasing the amplitude of movement after each successive actions of the force. However, this effect can be destructive in some rigid materials.

Passengers on the train, and flies on the passengers, can be sleeping or reading books. In their reference frames, the train is not moving.

Using the given equation you get:

E = 1.99x10^-25 / 9.0x10^-6

Divide 1.99 by 9.0: 1.99/9.0 = 0.22

For the scientific notation, when dividing subtract the two exponents:

25 -6 = 19

So you now have 0.22 x 10^-19

Now you need to change the 0.22 to be in scientific notation form:

2.2 x 10^-20

The answer is B.

405j because kE=1/2mv^2

Answer: 405 J

Explanation:

i got it right on my exam

Answer:

It would not be possible the cohesion among water molecules by the polar covalent bonding.

Well, to understand this in a better way, let's begin by explaining that water is special due to its properties, which makes this fluid useful for many purposes and for the existence of life.

In this sense, one of the main properties of water is cohesion (molecular cohesion), which is the attraction of molecules to others of the same type. So, water molecule ([tex]H_{2}O[/tex]) has 2 hydrogen atoms attached to 1 oxygen atom and can  stick to itself through hydrogen bonds.

How is this possible?

By the polar covalent bonding, a process in which electrons are shared unequally between atoms, due to the unequal distribution of electrons between atoms of different elements. In other words: slightly positive and slightly negative charges appear in different parts of the molecule.  

Now, it can be said that a water molecule has a negative side (oxygen) and a positive side (hydrogen).  This is how the oxygen atom tends to monopolize more electrons and keeps them away from hydrogen. Thanks to this polarity, water molecules can stick together.

If water molecules did not have a slight negative charge on one end and a slight positive charge on the other, several important properties of water would be affected. These properties include the ability of water to form hydrogen bonds, its high boiling point, high surface tension, and its ability to dissolve substances. The polar nature of water molecules is essential for many of the unique properties and functions of water in biological systems and the environment.

If water molecules did not have a slight negative charge on one end and a slight positive charge on the other, several important properties of water would be affected. One of these properties is the ability of water molecules to form hydrogen bonds with each other. These hydrogen bonds allow water to have a high boiling point, high surface tension, and the ability to dissolve many substances. Without the polar nature of water molecules, these properties would be significantly altered.

For example, if water molecules were not polar, they would not be able to form hydrogen bonds, which are responsible for water's high boiling point. This means that water would evaporate more easily and at lower temperatures, making it difficult for organisms to survive in aquatic environments. Additionally, water's ability to dissolve other substances, such as salts and nutrients, would be reduced or eliminated altogether.

Answer:

[tex]1.0313\cdot 10^{12}[/tex]

Explanation:

The net charge is given by the sum of the charges of the protons and of the electrons:

[tex]Q=N_p q_p + N_e q_e[/tex]

where we have

[tex]Q=-5.00 nC=-5.00\cdot 10^{-9}C[/tex] is the net charge

[tex]N_p = 1.0\cdot 10^{12}[/tex] is the number of protons

[tex]q_p = +1.6\cdot 10^{-19}C[/tex] is the charge of one proton

[tex]N_e[/tex] is the number of electrons

[tex]q_e = -1.6\cdot 10^{-19}C[/tex] is the charge of one electron

Solving the equation for [tex]N_e[/tex], we find the number of electrons:

[tex]N_e = \frac{Q-N_p q_p}{q_e}=\frac{-5.0\cdot 10^{-9}C-(1.0\cdot 10^{12})(1.6\cdot 10^{-19}C)}{-1.6\cdot 10^{-19}C}=1.0313\cdot 10^{12}[/tex]

The speck of dust has 1.0312 x 10¹² electrons. This was calculated by first finding the number of extra electrons required to achieve the negative charge, and then adding this to the original number of protons.

Given the net charge of the speck of dust is −5.00 nc or -5.00 × 10^-9 Coulombs, and we are provided with a 1.0000×10¹² protons in it. Given that we know the fundamental charge e is equal to +1.602 x 10-¹⁹ C for a proton and -1.602 x 10-¹⁹ C for an electron respectively.

Since protons are positively charged and electrons are negatively charged, the charge of an atom or in this case, a speck of dust, is determined by the number of protons and electrons. Considering the charge of one electron, to find the number of electrons, we can use the following formula:

nr of electrons = net charge/charge of one electron

Just plug the values into the formula and solve:

nr of electrons = -5.00 × 10⁻⁹ C /  -1.602 × 10⁻¹⁹ C/e⁻ = 3.12×10¹⁰ electrons

However, we started with 1.0000 × 10¹² protons, therefore, to gain a negative charge, the speck of dust must have more electrons than protons:

Total electrons = nr of protons + nr of extra electrons .

This gives us:  = 1.0000 × 10¹² protons + 3.12×10¹⁰ electrons = 1.0312 x 10¹² electrons.

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The oxidation number is equal to the charge on the ion.N2 is the divalent ion so the charge on N2 is zero as both the nitrogen atom share same number of electron and have same electronegativity. The dipole moment of N2 is zero.Therefore the cxidation number of N2 is 0.

Answer:

the cxidation number of N2 is 0

Explanation:

Answer:

0.625 (62.5 %)

Explanation:

The production efficiency is equal to the rate between the energy converted into useful energy and the energy in input:

[tex]\eta = \frac{E_{useful}}{E_{in}}[/tex]

where in this case:

- the useful energy is 750 J (the energy used in cellular respiration)

- the energy in input is 1200 J (the energy taken by eating the seeds)

Substituting,

[tex]\eta = \frac{750 J}{1200 J}=0.625[/tex]

Which means an approximate efficiency of 62.5 %.

Answer:

pleading

Explanation:

the first step in a lawsuit where parties pass their claims and their defenses. the plaintiff or the one complaining states the issue while the defendant states his answer on the complain and his defense

Final answer:

The process of bringing a complaint and filing an answer in a civil lawsuit is known as the pleadings. Option c.

Explanation:

The process of bringing a complaint and filing an answer is known as the pleadings. In a civil lawsuit, pleadings are the formal documents filed with the court that outline the parties' respective legal positions. The plaintiff initiates this process by filing a complaint, alleging harm or injury, and the defendant responds with an answer, setting forth the grounds for defense. This stage is crucial for setting the case in motion and establishing the issues that will be addressed during the trial or settlement proceedings.

Answer:

0.0129 V

Explanation:

The magnitude of the induced emf in the circuit is given by:

[tex]\epsilon = \frac{\Delta \Phi}{\Delta t}[/tex]

where

[tex]\Delta \Phi[/tex] is the change in magnetic flux through the coil

[tex]\Delta t[/tex] is the time interval

To find the change in magnetic flux, we need to find the initial flux and the final flux.

The area of the coil is

[tex]A=\pi r^2 = \pi (0.35 m)^2=0.385 m^2[/tex]

The initial magnetic field is

[tex]B_i = 0.50 T[/tex]

so the initial flux is

[tex]\Phi_i = B_i A = (0.50 T)(0.385 m^2)=0.193 Wb[/tex]

While the final flux is zero, since the coil is completely out of the magnetic field:

[tex]\Phi_f = 0[/tex]

so the magnitude of the change in flux is

[tex]\Delta \Phi = |\Phi_f - \Phi_i|=|0-0.193 Wb|=0.193 Wb[/tex]

While the time interval is

[tex]\Delta t = 15 s[/tex]

so the induced emf is

[tex]\epsilon = \frac{0.193 Wb}{15 s}=0.0129 V[/tex]

Answer:

It would be a neutralization reaction if i do believe so

Explanation:

A Acid and an Base Neutralize each other you have something too acidic you use a base to neutralize it and same goes for if it is too basic meaning you would use an acid to neutralize it.

Hope it helps =)

Answer: C) neutralization

Explanation:-

B. Ionization is a process in which the most loosely bound electron is removed from an isolated gaseous atom.

[tex]M\rightarrow M^++e^-[/tex]

C. Neutralization is a special type of double replacement reaction in which acid and base combines to form salt and water.

[tex]HCl+NaOH\rightarrow NaCl+H_2O[/tex]

D. Redox is a chemical reaction in which oxidation and reduction tales place simultaneously.

[tex]M+N^+\rightarrow M^++N[/tex]

Answer:

= 2

Explanation:

During nuclear fusion, two lighter nuclei of elements combine to form heavy nucleus and also energy is released;

During the process of hydrogen fusion a nucleus of deuterium is formed from two protons with emission of a neutrino.

In this case deuterium fuses with hydrogen nuclei to form helium-3 and also release energy.

That is;

2/1 H + 1/1 H = 3/1 He + energy

Answer:

Is a Series Circuit

Explanation:

The circuit shown in the image is a series circuit, is considered as a closed circuit meaning that only has one path for the current to flow with all light bulbs in a row, the voltage applied to the circuit is equal to each voltage drop in the light bulb, if any light bulbs blow out, the current will not flow because the circuit is broken and the remaining light bulb would turn off.

GFCI outlets are found in wet areas is the true statement about a GFCI oulet

Answer: Option D.

Explanation:

            GFCI stands for Ground Fault Circuit Interrupter and also named as RCD (Residual Current Device). This is a kind of circuit breaker that cuts off electricity after detecting an imbalance between output and input currents. The switch protects household lines and sockets against overheating and possible fire.  

              GFCI protects the people and is mostly used in bathrooms or kitchen where electrical equipment is used. Also, it is available where the human body can get into contact with the floor or metal fixings that provide an alternative route to power in the event of a fault. These outlets are available in two versions: the circuit breaker installed in the control panel and receptacle type installed into the electrical box.