Answer:
[tex]2.0\cdot 10^2 N[/tex]
Explanation:
The cabinet does not move: this means that the net force acting on it is zero.
Along the horizontal direction, we have two forces:
- The push exerted by Bob, F = 200 N, forward
- The frictional force, [tex]F_f[/tex], which acts in the opposite direction (backward)
Since the net force must be zero, we have:
[tex]F-F_f = 0[/tex]
So solving the equation we can find the magnitude of the friction force:
[tex]F_f = F = 200 N=2.0 \cdot 10^2 N[/tex]
Which of the following quantities have the dimensions of a speed?
(1)at (2)at^2 (3) (2ax)^(1/2) (4)((2x)/a)^(1/2)
Dimension of speed =
Other dimension =
Answer:
(1) and (3)
Explanation:
Speed has dimensions of:
m/s (meters per second)
While:
a (acceleration) has dimensions of [tex]m/s^2[/tex]
t (time) has dimensions of [tex]s[/tex]
Let's analyze each option:
(1)at
[tex](m/s^2) \cdot (s) = m/s[/tex] --> this has dimensions of speed
(2)at^2
[tex](m/s^2) \cdot (s)^2 = m[/tex] --> this has dimensions of distance
(3) (2ax)^(1/2)
[tex]\sqrt{(m/s^2)\cdot (m)}=m/s[/tex] --> this has dimensions of speed
(4) ((2x)/a)^(1/2)
[tex]\sqrt{\frac{m}{m/s^2}}=s[/tex] --> this has dimensions of time
So choices (1) and (3) are correct.
The quantities at and (2ax)^(1/2) have dimensions of speed because both, when calculated dimensionally, result in L/T or LT^-1, which is the dimensional representation of speed.
Explanation:The question is asking which of the given quantities have dimensions that could represent speed. The dimension of speed is given by L/T or LT-1, which means length divided by time. Speed itself is defined as the distance traveled over time, or ds/dt. Given that the dimensions provided for s (displacement) are [s] = L, and the dimensions of t (time) are [t] = T, any quantity that has dimensions of L multiplied or divided by T to the power of 1 is dimensionally equivalent to speed.
Using this information, we can analyze the given quantities:
at: Given [a] = LT-2 and [t] = T, at does have dimensions of L, but since [at] = LT-2T = LT-1, it represents speed.at2: Given [a] = LT-2 and [t2] = T2, at2 has dimensions L, but since [at2] = LT-2T2 = LT, it does not represent speed.(2ax)1/2: Given [a] = LT-2 and [x] = L, (2ax) has dimensions L2T-2, so [(2ax)1/2] = (L2T-2)1/2 = LT-1, which represents speed.((2x)/a)1/2: Given [x] = L and [a] = LT-2, (2x/a) has dimensions T2, so [((2x)/a)1/2] = (T2)1/2 = T, which does not represent speed.Therefore, the quantities that have dimensions of a speed are at and (2ax)1/2.
The charge on the square plates of a parallel-plate capacitor is Q. The potential across the plates is maintained with constant voltage by a battery as they are pulled apart to twice their original separation, which is small compared to the dimensions of the plates. The amount of charge on the plates is now equal to
A)4Q
B)2Q
C)Q
D)Q/2
E)Q/4
Answer:
D) Q/2
Explanation:
The amount of charge on a capacitor is given by:
Q = CV
where
C is the capacitance
V is the voltage
The capacitance of a parallel-plate capacitor is given by
[tex]C=\epsilon_0 \frac{A}{d}[/tex]
where
[tex]\epsilon_0[/tex] is the vacuum permittivity
A is the area of the plates
d is the separation between the plates
Substituting the last formula into the first one, we can write
[tex]Q=\epsilon_0 \frac{AV}{d}[/tex]
In this problem, the two plates are pulled apart to twice their original separation, so
d' = 2d
While the voltage V is kept constant. Therefore, the new charge stored in the capacitor will be
[tex]Q'=\epsilon_0 \frac{AV}{2d}=\frac{1}{2} \epsilon_0 \frac{AV}{d}=\frac{Q}{2}[/tex]
Option D is right.The amount of charge on the plates is now equal to Q/2.Charges are stores in the plate placed parallel referred as the parallel plate capacitor.
What is parallel plate capacitor ?
It is an type capacitor is an in which two metal plates arranged in such away so that they are connected in parallel and having some distance between them.
A dielectric medium is must in between these plates help to stop the flow of electric current through it due to its non-conductive nature .
The value of charge force the capacitor is given as:
Q = CV
[tex]\epsilon_0[/tex] is the vacuum permittivity
A is the area of the plates
d is the separation between the plates
The value of capacitance of a parallel-plate capacitor is given by the formula;
[tex]\rm C= \epsilon_0\frac{AV}{d}[/tex]
If all the values are constant then the charge is inversely proportional the distance between the charge.
Hence if the distance is doubled in that condition the value of charge will also half.
d' = 2d
While the voltage V is kept constant. Therefore, the new charge stored in the capacitor will be
[tex]\rm Q'= \frac{Q}{2}[/tex]
Hence option D is right.The amount of charge on the plates is now equal to Q/2.
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In which type of chemical reaction are electrons transferred
Answer:
Redox reactions
Explanation:
Redox (Reduction-Oxidation) reactions are reactions which involves the transfer of electrons. Here, one specie loses electrons while the other gains the electrons. The loss and gain of electrons makes one atom reduced while the other becomes oxidized. Transfer of electrons from one specie to another would eventually lead to a change in oxidation number of the reactants as they proceed to form products.
In non-redox reactions, there is no loss or gain of electrons and no change in oxidation number. An example is neutralization reaction.
How do mechanical and chemical digestion work together to break down food
Answer:
Explanation:
Digestion is the breaking down of food in order to release energy for the body. The body obtains its required nutrients through the process of digestion. In digestion, food is broken down and energy is released.
Mechanical digestion involves the breakage of food into tiny bits. Chemical digestion uses chemicals secreted in the body to completely and finally breakdown food.
Mechanical digestion helps the course of chemical digestion. In mechanical digestion, food is broken down by chewing, cudding, churning e.t.c. Here large chunks of food are broken down into tiny bits. The tiny fragments of food has more surface area than the bulk mass. Increase in surface area makes chemical reactions on food very fast. As the food is being subjected to mechanical breakage, chemical action takes place simultaneously.
The food being broken would then be mixed with chemical substances in the body for proper breakage. Chemical digestion completes the digestive process. Chemically digested food can easily be taken into the blood stream where they are transported to different sites within the body.
Mechanical and chemical digestion work in tandem to break down food into nutrients that our bodies can utilize. Mechanical digestion physically breaks down the food, while chemical digestion uses enzymes to break down the compounds in food. Both processes start in the mouth and continue on through the digestive system.
Explanation:Mechanical and chemical digestion work together to break down food that we consume. Mechanical digestion starts in the mouth where food is physically broken down into smaller pieces through the process of chewing, making the food easier to swallow and increasing the surface area. The stomach further continues this process with its muscular contractions.
Meanwhile, chemical digestion involves the use of various enzymes throughout the digestive system, including in the mouth, stomach, and small intestine, to break down the food's compounds into nutrients that the body can use.
The process starts in the mouth where saliva breaks down carbohydrates, then continues in the stomach where gastric acid breaks down proteins, and finally in the small intestine where enzymes work on fats and remaining carbohydrates and proteins. Together, these two forms of digestion ensure that our bodies can absorb and use the nutrients we eat.
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Due to alcohol's effect on your sense of balance, you may
A. Be unaware when you're driving on a hill
B. Feel like you're falling
C. Make unnecessarily wide gestures
Final answer:
Alcohol's effect on the sense of balance can make you feel like you're falling by disturbing the brain's ability to coordinate movements, which is crucial when planning to drive or operate machinery.
Explanation:
Due to alcohol's effect on your sense of balance, you may Feel like you're falling. Alcohol affects the cerebellum, a part of the brain that helps coordinate movements and balance. When alcohol enters the system, it disturbs the delicate balance between the motor command from the primary motor cortex to the proprioceptive and vestibular sensory feedback. This disturbance causes difficulties in maintaining balance, making activities such as walking in a straight line challenging.
It directly affects how we perceive our orientation in space, leading to a sensation of falling or instability. This effect on balance is especially problematic when planning to drive, operate machinery, or engage in activities requiring coordination and alertness. Furthermore, the consumption of alcohol, even in moderate amounts, can significantly impair driving performance and other activities requiring fine motor skills and cognitive function.
An athlete is working out in the weight room. He steadily holds 50 kilograms above his head for 10 seconds. Which statement is true about this situation? A. The athlete isn't doing any work because he doesn't move the weight. B. The athlete isn't doing any work because he doesn't hold the weight long enough. C. The athlete is doing work because he prevents the weight from falling downward. D. The athlete is doing work because 50 kilograms is a significant load to lift.
Answer:
A. The athlete isn't doing any work because he doesn't move the weight.
Explanation:
As we know that work done is defined as the product of force and displacement of the object in the direction of the force
so here we can say
[tex]W = F d cos\theta[/tex]
now we know that here force is applied by the athlete to hold the mass but the mass is steady at its position
The mass is not moving so we can say that
[tex]d = 0[/tex]
so the work done by the athlete will be zero
so correct answer is
A. The athlete isn't doing any work because he doesn't move the weight.
What does the atomic mass of an atom tell us?
How much the atom weighs
The number of electrons in the atom
Which row the element is in on the periodic table
The number of energy levels in the atom
"The atomic mass of an atom tells us the mass of an atom relative to carbon-12, which is assigned a mass of exactly 12 atomic mass units (amu). It is approximately equal to the sum of the number of protons and neutrons in the nucleus of an atom. The correct answer to the question is: How much the atom weighs.
The atomic mass is a measure of the mass of a single atom, and it is useful for comparing the masses of different atoms. It is important to note that the atomic mass is not an absolute measure of mass, but a relative one, based on the carbon-12 standard. The atomic mass listed on the periodic table for a given element is the weighted average of the masses of all the naturally occurring isotopes of that element.
To clarify the other options: - The number of electrons in the atom: This is indicated by the atomic number, not the atomic mass. The atomic number is the number of protons in the nucleus of an atom, and for a neutral atom, it is also equal to the number of electrons.
- Which row the element is in on the periodic table: The period (row) in which an element is located on the periodic table is determined by the number of electron shells or energy levels in the atom. This is related to the atomic number, not the atomic mass.
- The number of energy levels in the atom: Similar to the period in which an element is located, the number of energy levels (or electron shells) is also determined by the atomic number and not the atomic mass. The electron configuration of an atom, which is related to its position in the periodic table, dictates the number of energy levels."
The jovian moon with the most geologically active surface is
Io is the moon closest to Jupiter and is considered the most geologically active object in the solar system.
This is because very extensive plains rich in sulfur and sulfur dioxide, mountain ranges (mountains with an average height of about 6 km), and many volcanic formations on its surface have been observed.
As for the volcanoes, Io at least has many eruptions more or less continuous, which has very important effects on its topography, since the crust is in a process of constant renewal. This explains why no impact craters have been observed on its surface, as the continuous eruptions and lava flows cover them shortly after they occur.
Io is the jovian moon with the most geologically active surface.
Explanation:The jovian moon with the most geologically active surface is Io. Io is one of Jupiter's moons and is known for its high level of volcanism, exceeding that of Earth. It has a surface scarred by volcanic activity, making it the most volcanically active body in our solar system.
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based on the information in the graph why is energy released during the fission of a uranium (U) nucleus?
Answer:
D
Explanation:
Fission is the break of the nuclei of an unstable atom, releasing heat in the process. By the graph shown, U-238 has less average binding energy per nucleon comparing to U-235. Because it has less binding energy, it is more difficult for it to react (it has less energy to release), so it is more stable than U-235.
The product of its fission is the U-235, an isotope that has a small mass than the uranium. So the mass that is lost during fission is converted to the binding energy in the isotope, making it slightly higher (the difference of mass is only 3 amu).
Which sentences describe point source pollution? In this type of pollution, the source of the pollution is single and easily identifiable. When runoff water from the melting of snow mixes with debris, it creates pollution. The runoff water, mixed with pollutants, reaches large areas with disastrous effects. Alternatively, when a wastewater treatment plant releases harmful chemicals into a stream, the chemicals pollute the stream water because they are not treated for safety.
Answer:
In this type of pollution, the source and of the pollution, the source of the is single and identifiable.
Explanation:
These sources are regulated by federal and state agencies and include conduit pipes, industrial discharge and sewerage treatment plants that release treated or untreated waste matter in to water bodies. They can therefore possibly be directly controlled by human decision.
Answer:
"In this type of pollution, the source of the pollution is single and easily identifiable." and "Alternatively, when a wastewater treatment plant releases harmful chemicals into a stream, the chemicals pollute the stream water because they are not treated for safety."
Explanation:
Just took the test for PLATO
please help i will vote brainliest!
Answer:
C
Explanation:
The force of gravity on an object varies directly with its mass. The constant of variation due to gravity is 32.2 feet per second squared. Which equation represents F, the force on an object due to gravity according to m, the object’s mass?F = 16.1mF =F = 32.2mF =
Explanation:
According Newton's 2nd Law of Motion the force [tex]F[/tex] is directly proportional to the mass [tex]m[/tex] and to the acceleration [tex]a[/tex] of a body:
[tex]F=m.a[/tex] (1)
When we talk about the force of gravity on an object (the weight) the constant acceleration is due gravity, this means:
[tex]a=g=32.2ft/s^{2}[/tex] (2)
Substituting (2) in (1):
[tex]F=m(32.2ft/s^{2})[/tex] (3)
This means the equation that best represents the force on an object due to gravity according to its mass, among the given options is:
[tex]F=32.2m[/tex]
According to classical physics what should happen as a filament in a light bulb gets hotter?
Answer:
it should give off light of increasing energy from red to violet and than into ultra violate
Explanation:
A filament in a light bulb gets hotter as B.it should give off light of increasing energy from red to violet and than into ultra violate.
Why does the filament get hot?
A typical light bulb contains a thin wire (usual tungsten) called a filament, which has a high electrical resistance. This filament becomes very hot when an electric current flows through it. Due to the high temperature, the filament shines brightly.
Incandescent lamps are common incandescent lamps. It contains a thin coil of wire called a filament. When an electric current flows, it gets hot and emits light. The resistance of the lamp increases as the temperature of the filament rises.
Filament temperatures are very high, usually above 2,000 ºC or 3,600 ºF. For a "standard" 60, 75, or 100-watt bulb, the filament temperature is about 2,550 ºC or about 4,600 ºF. At such high temperatures, the heat radiation from the filament contains a significant amount of visible light.
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When the temperature of an ideal gas is increased, what happens to its pressure?
Explanation:
The expression for an Ideal Gas is:
[tex]P.V=n.R.T[/tex]
Where:
[tex]P[/tex] is the pressure of the gas
[tex]n[/tex] the number of moles of gas
[tex]R[/tex] is the gas constant
[tex]T[/tex] is the absolute temperature of the gas
As we can see, there is a direct proportional relation between the temperature and the pressure, which means that if the temperature increases the pressure of the gas increases as well.
it can take some of those large , industrial vehicles up to ____ feet to stop when traveling only 60 MPH, and therefore , you shoukd be mindful to not be jn the traffic right in front of them
A. 100 feet
B. 200 feet
C. 335 feet
D. 425 feet
Answer:
a 200 feet, and trains go a whole mile even after hitting the brakes
Explanation:
it can take some of those large , industrial vehicles up to 200 feet to stop when traveling only 60 MPH. The correct option is B.
What are industrial vehicles?The vehicles like trucks or loaders transport the raw material or ready machines to the destination. They need to maintain a speed to timely reach the required location.
When these vehicles apply brakes, they will go as far as up to 200feet till they finally stop.
Thus, the correct option is B.
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Neither the surface nor the interior of the spherical conductor (map ii) and the neutral conductor (map iii) should be probed
a. True
b. False
It is true that neither the surface nor the interior of a spherical or neutral conductor should be probed. Probing would disrupt the conductor's charge distribution and could alter its electrical properties significantly.
Explanation:The statement is True. Both the spherical conductor and the neutral conductor are safe from being probed. This is because a conductor, whether spherical or neutral, distributes charges over its surface and generates electric fields that extend outward from that surface.
Therefore, introducing a probe to either the surface or the interior would disrupt this charge distribution and alter the properties of the conductor. The surface-charge density could change, leading to a subsequent alteration in the electric field surrounding the conductor. This action could potentially damage the conductor and distort any data being collected. Thus, neither the surface nor the interior of the conductors should ideally be probed.
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Does current flow through or across a resistor?
Answer:
Current flows across a resistor.
Explanation:
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It's not exactly clear what you think the difference is between "through" and "across".
A resistor has two wires. Electric current that flows into one wire, continues through the entire body of the resistor and out through the other wire. If there's a crack or break anywhere along the body of the resistor, the circuit will be 'open' and the current will stop flowing.
Now, if you were to connect a voltmeter between the ends of the resistor, the meter would measure and indicate the difference in electric potential between those two points. That would be called the voltage 'across' the resistor. Numerically, it would be equal to the product of the resistor's resistance and the current through it.
What property of objects is best measured by their capacitance?
Explanation:
The capacitance [tex]C[/tex] is defined as the relationship between the electric charge of each conductor and the potential difference between them. That is, it is the capacity of a device to store electrical charge.
In other words:
It is the property that bodies have to maintain an electric charge.
Mathematically it is defined as:
[tex]C=\frac{Q}{V}[/tex]
where:
[tex]C[/tex] is the capacitance value of a capacitor. Its unit is Farad [tex]F[/tex]; named in honor of the physicist Michael Faraday
[tex]Q[/tex] is the electric charge of the conductor, measured in coulombs [tex]C[/tex].
[tex]V[/tex]is the electric potential to which the conductor is located, measured in Volt.
The property of objects best measured by their capacitance is their ability to store electrical charge.
Explanation:The property of objects that is best measured by their capacitance is their ability to store electrical charge. Capacitance is a measure of how much charge an object can hold per unit voltage. It depends on the size and shape of the object, as well as the material between its conductive plates or electrodes.
Capacitors are devices that are specifically designed to have a high capacitance. They are used in many electronic circuits to store and release electrical energy. The capacitance of a capacitor can be increased by increasing the area of the plates, decreasing the distance between them, or changing the dielectric material between them.
Measuring capacitance is important in various applications, such as designing and optimizing electronic circuits, as well as understanding the behavior of electrical systems in general.
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A car of mass 960.0 kg accelerates away from an intersection on a horizontal road. When the car speed is 51.1 km/hr (14.2 m/s), the net power which the engine supplies is 3700.0 W (in addition to the extra power required to make up for air resistance and friction). Calculate the acceleration of the car at that time.
Answer:
[tex]0.27 m/s^2[/tex]
Explanation:
The power supplied by the engine is given by
P = Fv
where
F is the force applied
v is the velocity of the car
Here we have
P = 3700 W
v = 14.2 m/s
So we can solve the equation to find the average force:
[tex]F=\frac{P}{v}=\frac{3700 W}{14.2 m/s}=260.6 N[/tex]
The net force applied on the car is also equal to
F = ma
where
m = 960.0 kg is the mass of the car
a is the acceleration
Re-arranging the equation, we find the acceleration:
[tex]a=\frac{F}{m}=\frac{260.6 N}{960.0 kg}=0.27 m/s^2[/tex]
When two point charges are a distance d part, the electric force that each one feels from the other has magnitude F. In order to make this force twice as strong, the distance would have to be changed to
A) 2d
B) d/2
C) sqrt2*d
D) d/4
E) d/sqrt2
Answer:
E) d/sqrt2
Explanation:
The initial electric force between the two charge is given by:
[tex]F=k\frac{q_1 q_2}{d^2}[/tex]
where
k is the Coulomb's constant
q1, q2 are the two charges
d is the separation between the two charges
We can also rewrite it as
[tex]d=\sqrt{k\frac{q_1 q_2}{F}}[/tex]
So if we want to make the force F twice as strong,
F' = 2F
the new distance between the charges would be
[tex]d'=\sqrt{k\frac{q_1 q_2}{(2F)}}=\frac{1}{\sqrt{2}}\sqrt{k\frac{q_1 q_2}{(2F)}}=\frac{d}{\sqrt{2}}[/tex]
so the correct option is E.
The frequency of the middle c note on a piano is 261.63 hz. What is the wavelength of this note in centimeters? The speed of sound in air is 343.06 m/s.
Answer:
1.31 m
Explanation:
The relationship between frequency and wavelength of a sound wave is
[tex]c=f \lambda[/tex]
where
c is the speed of the wave
f is the frequency
[tex]\lambda[/tex] is the wavelenfth
In this problem, we have
c = 343.06 m/s
f = 261.63 Hz
So we can solve the formula for the wavelength:
[tex]\lambda=\frac{c}{f}=\frac{343.06 m/s}{261.63 Hz}=1.31 m[/tex]
Wavelength of the note of the piano is the ratio of speed of sound to its frequency. The wavelength of the note is centimeters is 131 centimeters.
What is wavelength of a wave?Wavelength of a wave is the distance between the two consecutive crest or the thrust of that wave. The wavelength of the wave is represented with the Greek latter lambda (λ).
The wavelength of the wave can be given as,
[tex]\lambda=\dfrac{v}{f}[/tex]
Here, (v) is the speed of wave and (f) is the frequency of the wave.
It is given that, the frequency of the middle c note on a piano is 261.63 hz.
As the speed of sound in air is 343.06 meter per second. Thus put the values of the known variables in the above formula to find the wavelength of the note as,
[tex]\lambda=\dfrac{343.06}{261.63}\\\lambda=1.31\rm m[/tex]
The wavelength of this note in centimeters is 131 centimeters.
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What accounts for an increase in the temperature of a gas that is kept at constant volume?
A. Energy has been removed as heat from the gas.
B. Energy has been added as heat to the gas.
C. Energy has been removed as work done by the gas.
D. Energy has been added as work done by the gas.
Answer:
B) Energy has been added as heat to the gas
Explanation:
I'm pretty much sure that this is the answer, it's been awhile since I've done thermodynamics but it should be alright.
An increase in the temperature of a gas that is kept at constant volume is because: B. Energy has been added as heat to the gas.
What is heat?Heat is also referred to as thermal energy and it can be defined as a form of energy that is transferred from one physical object to another, especially due to a difference in temperature.
Generally, heat is typically transferred between objects with different degrees of temperature and materials that are directly in contact with each other during the process of heat conduction.
For an ideal gas that is kept at constant volume, there is a change in its temperature because energy has been added as heat.
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How do I solve this question?
Explanation:
You can solve this with kinematics or with energy. It looks like you want to use energy.
Energy is conserved, so:
initial energy = final energy
Kinetic energy = potential energy
1/2 m v² = m g h
1/2 v² = g h
h = v² / (2g)
If we double the velocity:
H = (2v)² / (2g)
H = 4v² / (2g)
H = 4h
So the new height is 4h.
Relationship between electricity and magnetism
An artesian system is present when groundwater __________.
Explanation:
An artesian system is one that connects with an accumulation of water (aquifer) whose surface or level is above the surface of the system or well.
In other words, the upper limit of the aquifer is higher than the opening through which the liquid flows in the artesian well. This has the advantage that the water spreads without needing to be pumped.
It should be noted that its name comes from the region of Artois, France, where in 1126 the oldest well in Europe was drilled with these characteristics.
Therefore:
An artesian system is present when groundwater under pressure rises above the aquifer level.What percentage of a lower trophic level's energy flows to the next higher trophic level? A. 1% b. 10% c. 50% d. 100% Please select the best answer from the choices provided A B C D
Answer:
The answer is B; 10%
10 percentage of a lower trophic level's energy flows to the next higher trophic level.
What is meant by trophic level ?The trophic level is defined as the different levels in a food chain or the ecosystem, that consists of the organisms that are having the same functions in the food chain.
Here,
In each trophic levels, the organisms will be having the same nutritional relationship with their primary source of energy in the food chain.
There is a law regarding the energy transfer between the various trophic levels. It is known as the 10% law.
According to the 10% law, a 10 percentage of the energy from each of the lower trophic level is transferred to their higher levels in a food chain.
Even though some amount of energy is lost in the form of heat in the food chain.
Hence,
10 percentage of a lower trophic level's energy flows to the next higher trophic level.
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The topics covered by the study of thermodynamics include
a. energy changes during heating.
b. energy changes during chemical reactions.
c. color changes during chemical reactions.
d. Both (a) and (b)
The topics covered by the study of thermodynamics includes energy changes during heating. The correct option is a.
What is thermodynamics?Thermodynamics is the study of science in which heat energy is studied.
Thermodynamics include the laws of thermodynamics, internal energy, heat, work, PV diagrams, enthalpy, Hess's law, entropy, and Gibbs free energy.
Thus, the correct option is a.
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An electrically isolated object is electrically neutral. What is the charge on the object if you remove three electrons?
Answer:
[tex]+4.8\cdot 10^{-19}C[/tex]
Explanation:
The initial charge of the object is zero, since the object is neutral:
Q = 0
When we remove three electrons, we remove a charge of:
[tex]q' = 3 \cdot q_e[/tex]
where
[tex]q_e = 1.6\cdot 10^{-19}C[/tex] is the charge of one electron. Substituting,
[tex]q'=3 \cdot 1.6\cdot 10^{-19}C=-4.8\cdot 10^{-19} C[/tex]
So, the final charge on the initially neutral object will be
[tex]q=Q-q' = 0 - (-4.8\cdot 10^{-19} C)=+4.8\cdot 10^{-19}C[/tex]
How does the image distance (di) of a convex lens compare with the image distance of a concave lens?
A. The image distance of the convex lens is positive, and that of the concave lens is negative.
B. Both are negative for a virtual image.
C. Both are positive for a virtual image
D. The image distance of the convex lens is negative, and that of the concave lens is positive.
Explanation:
Image distance of a mirror is defined as the distance between the optical center and the formed image.
The image formed by a concave lens is virtual always. We can say that the image distance for a concave lens is negative. The convex lens or the converging lens can form both real and virtual images. So, the image distance for a convex lens can be either positive or negative. Generally, the image distance for convex lens is positive.
So, the correct option is (a) " The image distance of the convex lens is positive, and that of the concave lens is negative ".
Answer:
both are negative for a virtual image
Explanation:
A person travels by car from one city to another with different constant speeds between pairs of cities. She drives for 25.0 min at 95.0 km/h, 16.0 min at 100.0 km/h, and 50.0 min at 40.0 km/h and spends 30.0 min eating lunch and buying gas. Determine the average speed for the trip.
Answer:
49.8 km/h
Explanation:
We can determine the average speed by calculating the total distance covered and the time taken,
- First part of the trip:
v1 = 95.0 km/h = 26.4 m/s
t1 = 25.0 min = 1500 s
Distance covered:
[tex]d_1 = v_1 t_1 = (26.4 m/s)(1500 s)= 39600 m = 39.6 km[/tex]
- Second part of the trip:
v2 = 100.0 km/h = 27.8 m/s
t2 = 16.0 min = 960 s
Distance covered:
[tex]d_2 = v_2 t_2 = (27.8 m/s)(960 s)=26688 m= 26.7 km [/tex]
- Third part of the trip:
v3 = 40.0 km/h = 11.1 m/s
t3 = 50.0 min = 3000 s
Distance covered:
[tex]d_3 = v_3 t_3 = (11.1 m/s)(3000 s)=33300 m = 33.3 km [/tex]
The person also spend 30.0 min without moving:
t4 = 30.0 min = 1800 s
Total distance covered:
[tex]d=d_1 +d_2 +d_3 = 39.6 km +26.7 km + 33.3 km =99.6 km[/tex]
Total time taken:
[tex]t=t_1 +t_2 +t_3+t_4 = 1500 s+ 960 s+ 3000 s+1800 s=7260 s = 2.0 h[/tex]
So, the average speed is
[tex]v=\frac{d}{t}=\frac{99.6 km}{2.0 h}=49.8 km/h[/tex]