Which sentence correctly describes a friction force? A. It acts in the same direction as the motion of an object. B. It acts in a direction opposite to the motion of an object. C. It acts in the same direction as the force of gravity on an object. D. It acts in a direction perpendicular to the motion of an object.

(a) 18717 N

Newton's second law in this situation can be written as:

[tex]\sum F = T-W = ma[/tex] (1)

where

T is the tension in the cable, pointing upward

W is the weight of the elevator+passengers, pointing downward

m is the mass of the elevator+passengers (1700 kg)

a is the acceleration of the system (1.20 m/s^2, upward)

The weight is equal to the product between the mass, m, and the gravitational acceleration, g:

[tex]W=mg=(1700 kg)(9.81 m/s^2)=16,677 N[/tex]

So now we can solve eq.(1) to find T, the tension in the cable:

[tex]T=W+ma=16,677 N +(1700 kg)(1.20 m/s^2)=18,717 N[/tex]

(b) 16677 N

In this situation, the elevator is moving with constant velocity: this means that its acceleration is zero,

a = 0

So Newton's second law becomes

[tex]\sum F = T-W = 0[/tex]

and so we find

[tex]T=W=16,677 N[/tex]

(c) 15657 N

During the deceleration phase, Newton's second law can be written as:

[tex]\sum F = T-W = ma[/tex] (1)

Where the acceleration here points downward (because the elevator is decelerating), as the weight W, so we can write it as a negative number:

a = -0.600 m/s^2

we can solve the equation to find T, the tension in the cable:

[tex]T=W+ma=16,677 N +(1700 kg)(-0.600 m/s^2)=15,657 N[/tex]

(d) 19.35 m, 0 m/s

Distance covered during the first part of the motion; we know that

u = 0 is the initial velocity

a = 1.20 m/s^2 is the acceleration

t = 1.50 s is the time

So the distance covered is given by

[tex]d_1=ut + \frac{1}{2}at^2 = (0)(1.50 s)+\frac{1}{2}(1.20 m/s^2)(1.50 s)^2=1.35 m[/tex]

and the final velocity after this phase is

[tex]v_1=u+at=0+(1.20 m/s^2)(1.50 s)=1.8 m/s[/tex]

During the 2nd part of the motion, the elevator moves at constant speed of 1.8 m/s for t=8.50 s, so the distance covered here is

[tex]d_2 = v_1 t =(1.8 m/s)(8.50 s)=15.3 m[/tex]

Finally, in the third part the elevator decelerates at a = -0.600 m/s^2 for t = 3.00 s. So, the distance covered here is

[tex]d_3 = v_1 t + \frac{1}{2}at^2=(1.8 m/s)(3.00 s) + \frac{1}{2}(-0.600 m/s^2)(3.00 s)^2=2.7 m[/tex]

and the final velocity is

[tex]v_3 = v_1 +at = 1.8 m/s +(-0.600 m/s^2)(3.00 s)=0[/tex]

and the total distance covered is

[tex]d=d_1 +d_2+d_3=1.35 m+15.30 m+2.70 m=19.35 m[/tex]

Answer:

distance = 6 m

Explanation:

- Distance is a scalar quantity (so, only magnitude, no direction), and it is calculated as the scalar sum of all the distances travelled by an object during its motion, regardless of the direction. So, in this problem, the distance covered by the pinecone is

d = 4 m + 2 m = 6 m

- Displacement is a vector quantity (magnitude+direction), and its magnitude is calculate as the distance in a straight line between the final position and the initial position of the object. In this case, the final position is 2 m west and the initial position is 0 m, so the displacement of the pinecone is

d = 2 m west - 0 m = 2 m west

So, a scalar quantity from this scenario is

distance = 6 m

Answer:

Activation Energy

Explanation:

Effective collisions are those that result in a chemical reaction. In order to produce an effective collision, reactant particles must possess some minimum amount of energy. This energy, used to initiate the reaction, is called the activation energy.

Answer:

[tex]-1.6\cdot 10^{-18}C[/tex]

Explanation:

The charge of a single electron is:

[tex]q=-1.6\cdot 10^{-19}C[/tex]

If the oil droplet has N electrons, the total charge of the droplet will be

[tex]Q=Nq[/tex]

In this case, we have

N = 10

Therefore, the total charge on the droplet is

[tex]Q=(10)(-1.6\cdot 10^{-19} C)=-1.6\cdot 10^{-18}C[/tex]

In Millikan's experiment, the charge on any negatively charged oil droplet is always a whole-number multiple of the fundamental charge of a single electron. If the oil droplet had 10 negatively charged electrons, Millikan would have measured a charge of [tex]-1.60x10^-18[/tex] let.

Millikan's experiment involved measuring the charges on oil droplets that acquire negative charges by combining with the negative charges produced from the ionization of air by X rays. Millikan found that the charge on any negatively charged oil droplet is always a whole-number multiple of the fundamental charge of a single electron, which is [tex]-1.60x10^-19[/tex]

If Millikan was measuring the charge on an oil droplet with 10 negatively charged electrons on it, he would have measured a charge of[tex]-1.60x10^-19[/tex] y 10, which is [tex]-1.60x10^-18[/tex]

Answer:

There is a limit to the size of a stable nucleus because of the short range of the strong nuclear force

A stable nucleus contains nearly equal numbers of protons and neutrons

Explanation:

For an atom nucleus to be stable it has to have a balance between the strong nuclear forces keeping the protons and neutrons together against the repulsive electrostatic forces of the positively charged protons. When the nucleus is too large, the binding energy of the strong nuclear forces, that act over a short range,  may not be sufficient to hold the nucleus together hence causing instability.

Answer:

D) Zero newtons

Explanation:

According to the First Newton Law:

"An object keeps its state of rest or its state of uniform motion at constant velocity, when the net force acting on the object is zero"

In this problem, the hockey puck is initially set in motion. While in motion, there are no ice friction and air resistance acting on it: this means that the net force acting on it is zero, so there is no need for an additional force to keep the puck in its state of uniform motion at constant velocity, according to the abovementioned law.

Therefore, the correct answer is

D) zero newtons

In line with Newton's First Law of Motion, the force required to keep a hockey puck sliding at constant velocity on a frictionless surface is zero newtons, because it moves at a constant velocity unless acted upon by an unbalanced force.

The answer is D) zero newtons. According to Newton's First Law of Motion, an object will continue to move at a constant velocity unless acted upon by an unbalanced force. When the hockey puck is in motion on a frictionless surface, it keeps moving at a steady velocity without the need for an additional force. The net force acting on the puck is zero. Thus, no extra force is required to maintain its constant velocity.

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It takes approximately 88 Earth days for Mercury to orbit the sun.

Hope I helped, sorry if I'm wrong ouo.

~Potato

Copyright Potato 2019.

Answer:

87.96926 Days =88 days

Explanation:

Average speed 105,947 miles per hour.

Answer:

98 N

Explanation:

The weight of an object is given by

W = mg

where

m is the mass of the object

g = 9.8 m/s^2 is the acceleration of gravity

Here we have an object with mass

m = 10 kg

Therefore, its weight will be

[tex]W=(10 kg)(9.8 m/s^2)=98 N[/tex]

Answer:

Radiation is the correct answer for this question.

Explanation:

Answer:

The order is:

Radioactive decay produces heat.

Boiling water produces steam.

Steam spins turbines.

Electricity is generated.

Explanation:

A nuclear power plant uses heat from nuclear reactions to create steam from water. This steam spins turbines, which generate electricity.

A nuclear power plant produces electricity using the heat generated by the nuclear reactions or radioactive decay within the reactor. The heat generated through this process is used to heat water, forming steam. Following this, in order:

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Power = (1000 kilo-Watt-hr/mo) x (1000/kilo) x (mo/30day) x (day/24 hr)

Power = (1000 x 1000 / 30 x 24) (kilo-watt-hr-mo-day/mo-kilo-day-hr)

Power = (1,000,000/720) watt

(voltage x current) = (1,000,000/720) watts

120v x current = (1,000,000/720) watts

Current =  1,000,000 / (720 x 120) Amperes

Current = 11.57 Amperes

The typical American home draws around an average effective (RMS) current of 11.58 amps from a 120 V power line.

The average current in the power line of a typical American house can be calculated using Ohm's law and the power equation. If a typical American family uses 1000 kWh per month, we need to convert this to average power in kW, which gives (1000 kWh) / (30 days*24 hours) = 1.39 kW = 1390 W.

Given that the voltage is 120 V, we can use the formula: P = IV, rearranging to find I = P/V. Therefore, I = 1390 W / 120 V = 11.58 A.

This means the power to a standard American home running at typical usage rates should draw an average effective(RMS) current of around 11.58 amps from a 120 V power line.

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Answer:

it will become a negatively charged ion

Explanation:

Answer:

The law of conservation of matter (or mass), also known as the Law of Lomonosov-Lavoisier, states the following:

"In a chemical reaction the sum of the mass of the reactants is equal to the sum of the mass of the products."

Hence the famous phrase:

"The mass is not created or destroyed, it only transforms."

This was raised by the Russian scientist Mikhail Lomonosov in 1748 and independently discovered years later by the French chemist Antoine Lavoisier in 1785.

It should be noted that this principle is quite accurate for low-energy chemical reactions, but for nuclear reactions (collisions between particles at high energies), this classical definition does not apply (the total mass of the system does not have to be strictly conserved) and must be taken into account the equivalence between mass and energy that was postulated in Albert Einstein's theory of relativity:

 "The amount of mass-energy that manifests a certain space-time is constant throughout the universe."

Being this expressed mathematically by his famous equation where he relates the energy [tex]E[/tex] with the mass [tex]m[/tex] and the speed of light [tex]c[/tex]:

[tex]E=mc^{2} [/tex]

Answer:

Matter cannot be created or destroyed.

Explanation:

APEX

Answer:

Bright spot

Explanation:

When we have interference between two identical and coherent beams, the conditions for constructive interference (bright spots) and destructive interference (dark spots) are:

- Costructive interference: the path-length differences between the two waves is an integer multiple of the wavelength of the waves:

[tex]|d_1 - d_2| = n \lambda[/tex]

where the term on the left is the path difference, and [tex]\lambda[/tex] is the wavelength

- Destructive interference: the path-length differences between the two waves is an odd multiple of half the wavelength of the waves:

[tex]|d_1 - d_2| = (n+\frac{1}{2}) \lambda[/tex]

In this problem, the path-length difference is 2 wavelengths: so, it is an integer multiple of the wavelength, therefore the point is a point of constructive inteference (bright spot).

A path-length difference of two wavelengths between two coherent beams results in a bright spot on the screen due to constructive interference. This is related to double slit experiments, which display evenly spaced bright fringes.

If two identical and coherent beams of light have a path-length difference of two wavelengths when they arrive on a screen, they will produce a bright spot. This is because a path-length difference of an integer number of wavelengths, such as two wavelengths, results in constructive interference. Constructive interference occurs when the crest of one wave overlaps with the crest of another, leading to an increase in amplitude and thus a bright fringe on the screen. This principle is at work in both single and double slit experiments.

In the context of single slit and double slit interference, evenly spaced bright spots are a characteristic of double slit experiments. On the other hand, the observation that some bright spots are dimmer on either side of the center is typical in single slit interference patterns because of the different path lengths and resulting interference effects.

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Troposhere is differ from stratosphere by the following reason

1. all weather pheonamena take place in trosphere

2. in trosposphere temperature increase by increasing height which is just opposite in the case of stratosphere

3. the maximum air is found in trosposphere

Final answer:

The troposphere is the earthly atmospheric layer where weather and major atmospheric changes take place due to its high density and temperature that decreases with altitude. Above it sits the stratosphere, which contains the ozone layer, and exhibits a temperature inversion, stability, and a lack of weather phenomena.

Explanation:

Comparison of Troposphere and Stratosphere

The troposphere and stratosphere are the two lowest layers of the Earth's atmosphere. The troposphere is the bottommost layer, where nearly all weather occurs and which houses most of the atmospheric mass. This layer extends from sea level up to about 9 km at the poles and averages 12 km in thickness, reaching up to 17 km at the equator due to the Earth's rotation. The troposphere is characterized by a temperature that decreases with altitude, making it denser near the surface. By contrast, the stratosphere is the second layer that lies above the troposphere, stretching from approximately 12 km to 50 km above Earth's surface. It contains the ozone layer and is known for its temperature inversion, where temperature increases with altitude due to the absorption of ultraviolet radiation by ozone.

The most discernible difference between the troposphere and the stratosphere is the temperature gradient. In the troposphere, temperature generally decreases with altitude, while in the stratosphere, it increases with altitude due to the presence of the ozone layer which absorbs and scatters the Sun's ultraviolet light. This temperature inversion creates a stable layer that prevents convective currents, marking a clear boundary between these two atmospheric layers known as the tropopause.

The troposphere is significantly more turbulent and dynamic, housing all the weather systems and majority of the atmospheric water vapors. Meanwhile, the stratosphere maintains a more stable environment. The difference in density and temperature between the two layers is responsible for the distinctive weather phenomena and atmospheric conditions unique to each layer.

Answer:

5.0

Explanation:

because 50.0 / 10.0 equals 5

A) 16.1 N

The magnitude of the electric force between the corks is given by Coulomb's law:

[tex]F=k\frac{q_1 q_2}{r^2}[/tex]

where

k is the Coulomb's constant

[tex]q_1 = 6.0 \mu C=6.0 \cdot 10^{-6} C[/tex] is the magnitude of the charge on the first cork

[tex]q_2 = 4.3 \mu C = 4.3 \cdot 10^{-6}C[/tex] is the magnitude of the charge of the second cork

r = 0.12 m is the separation between the two corks

Substituting numbers into the formula, we find

[tex]F=(9\cdot 10^9 N m^2 C^{-2} )\frac{(6.0\cdot 10^{-6}C)(4.3\cdot 10^{-6} C)}{(0.12 m)^2}=16.1 N[/tex]

B) Attractive

According to Coulomb's law, the direction of the electric force between two charged objects depends on the sign of the charge of the two objects.

In particular, we have:

- if the two objects have charges with same sign (e.g. positive-positive or negative-negative), the force is repulsive

- if the two objects have charges with opposite sign (e.g. positive-negative), the force is attractive

In this problem, we have

Cork 1 has a positive charge

Cork 2 has a negative charge

So, the force between them is attractive.

C) [tex]2.69\cdot 10^{13}[/tex]

The net charge of the negative cork is

[tex]q_2 = -4.3 \cdot 10^{-6}C[/tex]

We know that the charge of a single electron is

[tex]e=-1.6\cdot 10^{-19}C[/tex]

The net charge on the negative cork is due to the presence of N excess electrons, so we can write

[tex]q_2 = Ne[/tex]

and solving for N, we find the number of excess electrons:

[tex]N=\frac{q_2}{e}=\frac{-4.3\cdot 10^{-6} C}{-1.6\cdot 10^{-19} C}=2.69\cdot 10^{13}[/tex]

D) [tex]3.75\cdot 10^{13}[/tex]

The net charge on the positive cork is

[tex]q_1 = +6.0\cdot 10^{-6}C[/tex]

We know that the charge of a single electron is

[tex]e=-1.6\cdot 10^{-19}C[/tex]

The net charge on the positive cork is due to the "absence" of N excess electrons, so we can write

[tex]q_1 = -Ne[/tex]

and solving for N, we find the number of electrons lost by the cork:

[tex]N=-\frac{q_1}{e}=-\frac{+6.0\cdot 10^{-6} C}{-1.6\cdot 10^{-19} C}=3.75\cdot 10^{13}[/tex]

Answer: [tex]6.268(10)^{-16}J[/tex]

Explanation:

The kinetic energy of an electron [tex]K_{e}[/tex] is given by the following equation:

[tex]K_{e}=\frac{(p_{e})^{2} }{2m_{e}}[/tex]   (1)

Where:

[tex]K_{e}=15eV=2.403^{-18}J=2.403^{-18}\frac{kgm^{2}}{s^{2}}[/tex]

[tex]p_{e}[/tex] is the momentum of the electron

[tex]m_{e}=9.11(10)^{-31}kg[/tex]  is the mass of the electron

From (1) we can find [tex]p_{e}[/tex]:

[tex]p_{e}=\sqrt{2K_{e}m_{e}}[/tex]    (2)

[tex]p_{e}=\sqrt{2(2.403^{-18}J)(9.11(10)^{-31}kg)}[/tex]  

[tex]p_{e}=2.091(10)^{-24}\frac{kgm}{s}[/tex]   (3)

Now, in order to find the wavelength of the electron [tex]\lambda_{e}[/tex]   with this given kinetic energy (hence momentum), we will use the De Broglie wavelength equation:

[tex]\lambda_{e}=\frac{h}{p_{e}}[/tex]    (4)

Where:

[tex]h=6.626(10)^{-34}J.s=6.626(10)^{-34}\frac{m^{2}kg}{s}[/tex] is the Planck constant

So, we will use the value of [tex]p_{e}[/tex] found in (3) for equation (4):

[tex]\lambda_{e}=\frac{6.626(10)^{-34}J.s}{2.091(10)^{-24}\frac{kgm}{s}}[/tex]    

[tex]\lambda_{e}=3.168(10)^{-10}m[/tex]    (5)

We are told the wavelength of the photon  [tex]\lambda_{p}[/tex] is the same as the wavelength of the electron:

[tex]\lambda_{e}=\lambda_{p}=3.168(10)^{-10}m[/tex]    (6)

Therefore we will use this wavelength to find the energy of the photon [tex]E_{p}[/tex] using the following equation:

[tex]E_{p}=\frac{hc}{lambda_{p}}[/tex]    (7)

Where [tex]c=3(10)^{8}m/s[/tex]  is the spped of light in vacuum

[tex]E_{p}=\frac{(6.626(10)^{-34}J.s)(3(10)^{8}m/s)}{3.168(10)^{-10}m}[/tex]  

Finally:

[tex]E_{p}=6.268(10)^{-16}J[/tex]    

Answer:

Uranium

Explanation:

The nuclear power plants on Earth work based on the principle of nuclear fission.

Nuclear fission occurs when a heavy unstable nucleus splits into lighter nuclei: in this process, the total mass of the final product is smaller than the mass of the initial heavy nucleus, so part of the mass is converted into energy according to Einstein's equation:

[tex]E=mc^2[/tex]

where E is the energy released when an amount of mass m is converted (c is the speed of light).

Generally, the "fuel" (the initial heavy unstable element) used in nuclear power plants is uranium. A nucleus of uranium is bombarded with slow neutrons, which cause the process of nuclear fission to start: the nucleus of uranium split into lighter nuclei, releasing also additional neutrons, which are used to start further nuclear reactions.

Answer:

Microwaves and radio waves

Explanation:

The electromagnetic spectrum is the classification of the electromagnetic waves according to their wavelength.

From shortest to longest wavelength, they are classified as follows:

Gamma rays < 6 pm

X-rays 6 pm - 10 nm

Ultraviolet 10 nm - 380 nm

Visible light 380 nm - 750 nm

Infrared radiation [tex]750 nm - 5 \mu m[/tex]

Microwaves [tex]5 \mu m -0.3 m[/tex]

Radio waves > 0.3 m

From the list, we see that infrared rays have shorter wavelength than microwaves and radiowaves.

Infrared rays have longer wavelengths than visible light and ultraviolet radiation, falling in the range of 0.74(5m) to 1 mm, and are typically emitted by objects near room temperature. They are lower in energy and frequency compared to ultraviolet radiation, and are responsible for the warming sensation experienced when absorbed by the skin.

In answer to your question: Infrared rays have a shorter wavelength than microwaves. Infrared radiation, including infrared rays, falls below visible light in the electromagnetic spectrum with longer wavelengths and shorter frequencies than visible light. It ranges from about 0.74 micrometers (5m) to 1 millimeter (mm), corresponding to frequencies roughly from 300 gigahertz (GHz) to 400 terahertz (THz). Infrared rays are of lower energy compared to not only visible light but also ultraviolet radiation, which has a shorter wavelength and higher frequency than both visible light and infrared radiation.

Objects near room temperature emit most of the thermal radiation in the infrared range. Infrared light is emitted or absorbed by molecules when they change their rotational-vibrational movements. The sensation of warmth we often associate with infrared waves is due to the absorption of this radiation by our skin, which causes molecules to vibrate and increase in kinetic energy.

Answer:

The refracted angle will be less than the angle of incidence and the speed of light is slower in the new medium (which is water) and is closer to the normal.

Try remembering this by using FST SFA (Fast Sofa)

                                             Fast -> Slow = Towards the normal

                                             Slow -> Fast = Away from normal

When the flashlight is in the air and the refracted ray enters the water, the angle of refraction will be less than the angle of incidence.

When the light ray falls on the surface with angle of incidence, the lights gets reflected in the same medium with angle of reflection. The remaining rays gets into the medium on the other side of the surface.

The refracted angle is always less than the angle of incidence and the speed of light is slower comparatively in the another medium.

Thus, when the flashlight is in the air and the refracted ray enters the water, the angle of refraction will be less than the angle of incidence.

Learn more about refracted ray.

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Answer:

The air pressure will increase.

Explanation:

Answer:The pressure of the gas in the bottle increases

Explanation:this is governed by Boyles law which states that at constant temperature,the volume of a gas is inversely proportional to it's pressure ,i.e mathematically V&1/P at constant temperature,this can be further arranged as P1V1=P2V2.the implication of this formula is that as volume of gases increases,it pressure is decreasing and vice versa.

It is important to note that the constant here is the absolute temperature of the bottle

Answer:

it increases by a factor 1.07

Explanation:

The peak wavelength of an object is given by Wien's displacement law:

[tex]\lambda=\frac{b}{T}[/tex] (1)

where

b is the Wien's displacement constant

T is the temperature (in Kelvins) of the object

given the relationship between frequency and wavelength of an electromagnetic wave:

[tex]f=\frac{c}{\lambda}[/tex]

where c is the speed of light, we can rewrite (1) as

[tex]\frac{c}{f}=\frac{b}{T}\\f=\frac{Tc}{b}[/tex]

So the peak frequency is directly proportional to the temperature in Kelvin.

In this problem, the temperature of the object changes from

[tex]T_1 = 20.0^{\circ}+273=293 K[/tex]

to

[tex]T_2 = 40.0^{\circ}+273 = 313 K[/tex]

so the peak frequency changes by a factor

[tex]\frac{f_2}{f_1} \propto \frac{T_2}{T_1}=\frac{313 K}{293 K}=1.07[/tex]

Answer: 380 nm (violet-blue) and 780 nm (red)

Explanation:

The portion visible by the human eye of the electromagnetic spectrum is between 380 nm (violet-blue) and 780 nm (red) approximately.  

This part of the spectrum is located between ultraviolet light and infrared light.  

It should be noted that the fact only part of the whole electromagnetic spectrum is visible to humans is because the receptors in our eyes are only sensitive to these wavelengths.

Red goes in the first blank and violet goes in the second blank if you're using plato

Answer:

A

Explanation:

Initial gravitational energy = final kinetic energy + heat

mgh = KE + Q

(50 kg) (9.81 m/s²) h = 78400 J + 884000 J

h = 1960 meters

Answer:

D. Ultraviolet disinfecting wand.

Explanation:

Energy in light waves depends upon the frequency o the waves. Higher the frequency of the waves, higher the amount of energy it carries. Similarly, waves with shorter wavelength has higher frequencies and thus more energy.

Ultraviolet disinfecting wand would produce most energy out of the four options because it produce UV waves which have shorter wavelength and higher frequency.

Answer: (B): Radio-controlled airplane

Explanation:

A P E X

Answer:

The portion visible by the human eye of the electromagnetic spectrum is between 380 nm (violet-blue) and 780 nm (red) approximately.

This part of the spectrum is located between ultraviolet light and infrared light.

It should be noted that the fact only part of the whole electromagnetic spectrum is visible to humans is because the receptors in our eyes are only sensitive to these wavelengths.

Answer:

near the middle

Explanation:

for gradpoint anyway

Answer:

2000 kgm/s to the north.  

Explanation:

For any   colliding bodies, momentum must be conserved.

In this case we are required to find the momentum before collision.

Since the two cars are moving to different direction, we are going to take one velocity as negative.

∴ (900×10) + (1000× -7) = 9000 + - 7000

                                       = 9000 - 7000

                                       = 2000 kgm/s

Since the answer is positive and we had taken the velocity due north as positive, the combined momentum is 2000 kgm/s to the north.  

Answer:

6 m/s^2

Explanation:

The average acceleration of the car is given by:

[tex]a=\frac{v-u}{t}[/tex]

where

v is the final speed

u is the initial speed

t is the time elapsed

For the car in this problem,

v = 22 m/s

u = 4 m/s

t = 3 s

Therefore, the acceleration of the car is

[tex]a=\frac{22 m/s-4 m/s}{3 s}=6 m/s^2[/tex]

The inner atmosphere of a cloud chamber is composed of an easily ionizable gas, this means that little energy is required to extract an electron from an atom. This gas is maintained in the supercooling state, so that a minimum disturbance is enough to condense it in the same way as the water is frozen.  

This is how alpha particles are able to ionize some atoms of the gas contained inside the chamber when they cross the cloud chamber.

These ionized atoms increase the surface tension of the gas around it allowing it to immediately congregate and condense, making it easily distinguishable inside the chamber like a small cloud. In this way, it is perfectly observable the path the individual particles have traveled, simply by observing the cloud traces left in the condensed gas.