A friend asks you how much pressure is in your car tires. You know that the tire manufacturer recommends 30 psi, but it's been a while since you've checked. You can't find a tire gauge in the car, but you do find the owner's manual and a ruler. Fortunately, you've just finished taking physics, so you tell your friend, "I don't know, but I can figure it out." From the owner's manual you find that the car's mass is 1550 kg. It seems reasonable to assume that each tire supports one-fourth of the weight. With the ruler you find that the tires are 16 cm wide and the flattened segment of the tire in contact with the road is 14 cm long. What answer will you give your friend?

Answer:

Newton’s first law

Explanation:

An object at rest will stay at rest until moved on by a different object. And a object at motion will stay in motion until acted on by another object. There technically could be 2 that apply because the force could be Newton’s second law. Hope this helped :)

Final answer:

Newton's First Law of Motion, which states that a body at rest remains at rest unless acted upon by an external force, best describes the scenario of a stationary soccer ball being kicked into motion.

Explanation:

The scenario described in the question, where a soccer ball remains still until it is kicked, is best explained by Newton's First Law of Motion. This law, also sometimes referred to as the law of inertia, states that a body at rest will remain at rest unless acted upon by a net external force. In the case of the soccer ball, it remains stationary until the soccer player applies a force with their foot. Additionally, once in motion, the ball continues to move and only stops or changes direction due to external forces like gravity, air friction, or being caught by a goalkeeper. These forces are considered external as they are not part of the ball's internal structure.

Answer:

a) 0.750

Explanation:

When the unpolarized light passes through the first polarizer, it becomes polarized along the axis of transmission of the polarizer itself.

Then, the light passes through the second polarizer, whose axis of transmission is inclined by an angle [tex]\theta[/tex] with respect to the direction of polarization of the light.

Calling [tex]I_0[/tex] the initial intensity of the light, the intensity of light passing through the second filter is

[tex]I=I_0 cos^2 \theta[/tex]

where

[tex]\theta=30^{\circ}[/tex]

Solving the formula for [tex]\frac{I}{I_0}[/tex], which is the fraction of the incident intensity transmitted through the second polarizer, we find

[tex]\frac{I}{I_0}=cos^2 \theta = cos^2 30^{\circ}=0.750[/tex]

When unpolarized light passes through two polarizers whose transmission axes are at an angle of 30.0 degrees with respect to each other, the fraction of the incident intensity transmitted through the polarizers is 0.75.

When unpolarized light passes through two polarizers whose transmission axes are at an angle of 30.0 degrees with respect to each other, the fraction of the incident intensity transmitted through the polarizers can be calculated using Malus' Law.

Malus' Law states that the intensity of the transmitted light is equal to the initial intensity multiplied by the square of the cosine of the angle between the transmission axes of the polarizers.

In this case, the angle between the transmission axes is 30.0 degrees, so the fraction of the incident intensity transmitted through the polarizers is (cos(30.0))² = 0.75.

Answer:

A

Explanation:

a cell phone tower provides 1e+13 waves per second

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Answer:

21.3 V, 1.2 A

Explanation:

1.

These resistors are in series, so the net resistance is:

R = R₁ + R₂ + R₃

R = 20 + 30 + 45

R = 95

So the current is:

V = IR

45 = I (95)

I = 9/19

So the voltage drop across R₃ is:

V = IR

V = (9/19) (45)

V ≈ 21.3 V

2.

First, we need to find the equivalent resistance of R₂ and R₃, which are in parallel:

1/R₂₃ = 1/R₂ + 1/R₃

1/R₂₃ = 1/10 + 1/10

R₂₃ = 5

Now we find the overall resistance by adding the resistors in series:

R = R₁ + R₂₃ + R₄

R = 10 + 5 + 10

R = 25

So the current through R₁ is:

V = IR

30 = I (25)

I = 1.2 A

C. since the the heat from the heater is going to the child in waves, it’s radiating

The transfer of thermal energy through radiation is exemplified by a thermometer sitting on top of a heat lamp, representing energy transferred through electromagnetic waves without direct contact.

The answer which represents thermal energy transfer through radiation is A) a thermometer sitting on top of a heat lamp. This is because radiation is a method of heat transfer that does not rely on any contact between the heat source and the heated object, as in the case of a thermometer receiving infrared radiation from a heat lamp.

Radiation is the transfer of energy by electromagnetic waves, and it can occur even through a vacuum. For example, the glow of the sun or a candle flame is heat transfer by radiation; the energy is transferred in the form of visible light and other electromagnetic waves. The amount of power radiated is proportional to the surface area of the radiating object and increases significantly with the absolute temperature of the object, adhering to the relationship P ≈ T4, where P represents the radiated power and T is the absolute temperature in Kelvin.

Answer:

3600 V

Explanation:

The transformer equation states that:

[tex]\frac{V_p}{N_p}=\frac{V_s}{N_s}[/tex]

where

[tex]V_p = 120 V[/tex] is the voltage in the primary coil

[tex]N_p = 95[/tex] is the number of turns in the primary coil

[tex]V_s[/tex] is the voltage in the secondary coil

[tex]N_s = 2850[/tex] is the number of turns in the secondary coil

Slving the equation for Vs, we find the emf induced in the secondary coil:

[tex]V_s = \frac{V_p N_s}{N_p}=\frac{(120 V)(2850)}{95}=3600 V[/tex]

it is intensity. Option A

Actually, latitude is defined as the angular distance between the equatorial line and a specific point on the Earth. Dividing the planet in the northern hemisphere and the southern hemisphere, depending on the location of the geographical point with respect to the equator.

Now, imaginary horizontal lines that never touch (that is why they are parallel) that travel across the Earth globe from East to West, forming circles that become smaller and smaller as they get closer to the poles, are called parallels. Where the equator line is known as parallel [tex]0\°[/tex], and the degrees of latitude reach up to [tex]90\°[/tex]North or [tex]90\°[/tex]South.

So, the parallels allow us to determine the latitude of a point, in other words, they help to know if the position of a point is North or South of the Equator's parallel.

Plants absorb sunlight to fuel the process of photosynthesis, converting this light energy into chemical energy to produce glucose from carbon dioxide and water.

Plants get the energy they need for photosynthesis by absorbing sunlight. This light is captured primarily through their leaves, specifically, the chlorophyll in the chloroplasts, which converts light energy into chemical energy, a procedure known as light-dependent reactions.

This energy is then used to generate glucose from carbon dioxide and water in a process commonly referred to as the 'light-independent reactions', or the Calvin cycle.

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Answer:

2.5 m/s^2

Explanation:

the formula for acceleration (or the one you use in this case) is a=vf-vi/t

where vf is equal to final velocity, vi is equal to initial velocity, and t is equal to time.

vf= 25 m/s

vi= 0m/s

t=10s       25-0=25, 25/10=2.5 therefore it is 2.5m/s^2

Answer:

The force at the midpoint of the door.

Explanation:

The torque produced in the door will be:

              T = rFsinθ

Here θ = 90 degrees so,

               T = rF  

At the midpoint of the door the moment arm is half than that of doorknob. So, to produce same torque we have to apply two times force at the midpoint of the door than the force at doorknob.

The correct option is a.

In Physics, the concept of torque shows that the first force at the midpoint of the door has a greater magnitude than the second force at the doorknob, given that the torques are equal and distances from the door h-inge for both forces are different.

In the context of torque, the force that one applies on a door at different points creates differing results because of the concept of lever arm. Torque is calculated by multiplying the force applied by the distance from the pivot point, which in this case is the door h-inge. Therefore, if the torques are equal as proposed in the question and the distance for the second force (at the doorknob) from the h-inge is greater than the first force (at the midpoint), it must mean that the magnitude of the second force is less than the first for the torques to be equal. Thus, the first force (at the midpoint) has a greater magnitude.

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Answer:

Explanation:

“Officially, the decade with the most Category 5 hurricanes is 2000–2009, with eight Category 5 hurricanes having occurred: Isabel (2003), Ivan (2004), Emily (2005), Katrina (2005), Rita (2005), Wilma (2005), Dean (2007), and Felix (2007).”

The Earth takes (365 and 1/4) days to orbit the sun.  That's the length of our 'year'.

Since it's not really possible to make our calendar a quarter of a day longer every year, we make the calendar a whole day longer every 4 years.

So "Leap years" make up for the extra one-fourth day the Earth takes to orbit the sun.

(a) 1440.5 Hz

The general formula for the Doppler effect is

[tex]f'=(\frac{v+v_r}{v+v_s})f[/tex]

where

f is the original frequency

f is the apparent frequency

[tex]v[/tex] is the velocity of the wave

[tex]v_r[/tex] is the velocity of the receiver (positive if the receiver is moving towards the source, negative otherwise)

[tex]v_s[/tex] is the velocity of the source (positive if the source is moving away from the receiver, negative otherwise)

Here we have

f = 1110 Hz

v = 334 m/s

In the reflector frame (= on surface B), we have also

[tex]v_s = v_A = -28.7 m/s[/tex] (surface A is the source, which is moving towards the receiver)

[tex]v_r = +62.2 m/s[/tex] (surface B is the receiver, which is moving towards the source)

So, the frequency observed in the reflector frame is

[tex]f'=(\frac{334 m/s+62.2 m/s}{334 m/s-28.7 m/s})1110 Hz=1440.5 Hz[/tex]

(b) 0.232 m

The wavelength of a wave is given by

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

where

v is the speed of the wave

f is the frequency

In the reflector frame,

f = 1440.5 Hz

So the wavelength is

[tex]\lambda=\frac{334 m/s}{1440.5 Hz}=0.232 m[/tex]

(c) 1481.2 Hz

Again, we can use the same formula

[tex]f'=(\frac{v+v_r}{v+v_s})f[/tex]

In the source frame (= on surface A), we have

[tex]v_s = v_B = -62.2 m/s[/tex] (surface B is now the source, since it reflects the wave, and it is moving towards the receiver)

[tex]v_r = +28.7 m/s[/tex] (surface A is now the receiver, which is moving towards the source)

So, the frequency observed in the source frame is

[tex]f'=(\frac{334 m/s+28.7 m/s}{334 m/s-62.2 m/s})1110 Hz=1481.2 Hz[/tex]

(d) 0.225 m

The wavelength of the wave is given by

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

where in this case we have

v = 334 m/s

f = 1481.2 Hz is the apparent in the source frame

So the wavelength is

[tex]\lambda=\frac{334 m/s}{1481.2 Hz}=0.225 m[/tex]

Vegetal transpiration is the loss of water in the form of vapor, in the plant through its different parts, especially its leaves.

In this process, soil water is absorbed by the roots of the plant and transported in liquid form to the leaves to be converted into water vapor, while a part is used in photosynthesis. That is why vegetal transpiration is considered a vital function in the photosynthesis process.

This is possible because the leaves have small pores that allow water to escape into the atmosphere in the form of vapor and absorb carbon dioxide. Then, most of the water in the plants is used in the process of transpiration and only a small percentage is retained in liquid state and used for its growth and storage.

Answer:

Valence electrons

Explanation:

The valence electrons are found in the outermost shell of an atom. They are the most loosely held electrons found within an atom. These valence electrons are involved and are used to form bonds when atoms combines together.

The energy required to remove these loosely held electrons is relatively low compared to electrons located in the inner orbitals. This is why when atoms combines, they use the outermost electrons to form bonds and mimic stable atoms like those of the noble gases.

Valence electrons are those in the outermost shell of an atom; they are used to form bonds such as ionic and covalent bonds to achieve stable electron configurations. Atoms generally follow the octet rule where they seek eight valence electrons, although there are exceptions like hydrogen and transition elements.

The type of electron that is available to form bonds is known as the valence electron. Valence electrons are those electrons found in the outermost shell of an atom and are critical in determining how an atom will chemically interact with other atoms. Typically, atoms will form bonds to achieve a stable electron configuration, often striving to have eight valence electrons, following the octet rule. However, there are exceptions such as hydrogen, which only requires two electrons to fill its valence shell, and transition elements that do not always follow the octet rule due to their d and f electrons.

There are two main types of bonds that involve valence electrons: ionic bonds and covalent bonds. Ionic bonds occur when electrons are transferred from one atom to another, creating ions that are held together by electrostatic forces. Covalent bonds occur when electrons are shared between atoms, which can be envisioned as electron density located in space-symmetric wave functions between the nuclei of the bonded atoms.

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Answer:

True

Explanation:

Answer:

Parallel lines never intersect, but they must be in the same plane. The definition does not require the undefined term point, but it does require plane. Because they intersect, perpendicular lines must be coplanar; consequently, plane is not required in the definition.

What did you include in your response? Check all that apply.

Parallel lines do not intersect.

Parallel lines must be coplanar.

Perpendicular lines intersect at one point.

Perpendicular lines intersect  so plane is not required in the definition.

Answer:

Let's start by explaining that a material is a good electrical conductor when it allows the flow of electric current without  much resistance.  

This is achieved because the atoms of which the material is composed have electrons in their valence shell, which is the outermost layer where the electrons (the particles responsible for transporting electricity) can be easily detached to form atomic bonds, so there is no need of a huge amount of energy for these electrons to jump from one atom to another and form stable chemical bonds.

This is what happens with metals, because they have an atomic structure so united and stable that when an electric flow passes through it, the electrons in the metal flow unimpeded.

Metals are good conductors because the molecules that are inside the metal are tightly packed together. This is why the heat moves through the metal quickly.

Answer:

the escape speed from planet Y is [tex]\sqrt{2}[/tex] times the escape speed from planet X.

Explanation:

The escape speed from a surface of a planet is given by:

[tex]v=\sqrt{\frac{GM}{R}}[/tex]

where

G is the gravitational constant

M is the mass of the planet

R is the radius of the planet

Let's call M the mass of planet X and R its radius. So the speed

[tex]v_x=\sqrt{\frac{GM}{R}}[/tex]

corresponds to the escape speed from planet X.

Now we now that planet Y has:

- same radius of planet X: R' = R

- twice the density of planet X: d' = 2d

The mass of planet Y is given by

[tex]M' = d' V'[/tex]

where V' is the volume of the planet. However, since the two planets have same radius, they also have same volume, so we can write

[tex]M' = d' V= (2d)V = 2M[/tex]

which means that planet Y has twice the mass of planet X. So, the escape speed of planet Y is

[tex]v'=\sqrt{\frac{GM'}{R}}=\sqrt{\frac{G(2M)}{R}}=\sqrt{2}(\sqrt{\frac{GM}{R}})=\sqrt{2} v[/tex]

so, the escape speed from planet Y is [tex]\sqrt{2}[/tex] times the escape speed from planet X.

The escape speed from Planet Y, which has the same radius but twice the density as Planet X, would be approximately 28,300 m/s.

The escape speed, or escape velocity, from a planet is dependent on the mass and the radius of the planet, and it's calculated using the formula:

v = sqrt((2*G*M)/R)

Where v is the escape speed, G is the gravitational constant, M is the mass of the planet, and R is the radius of the planet. If Planet Y has the same radius as Planet X but is twice as dense, its mass will be twice that of Planet X because mass is density times volume. Thus, the escape speed from Planet Y will be sqrt(2) or approximately 1.414 times the escape speed from Planet X. So, v_Y = 1.414 * 20,000 m/s, or about 28,300 m/s.

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All clocks that keep the correct time have hands that move at the same speeds.  I only have to decide whether the famous clock in London keeps the correct time.  I'm thinking that if it didn't, it wouldn't have gotten to be so famous, or else the people of London would have fixed it by now.  So I'm going to assume that it keeps the correct time.

Since the famous clock in London keeps the correct time, its minute hand makes one complete revolution around the clock's face every hour, and its hour hand makes one complete revolution every 12 hours.  

When we're talking angular speeds, we usually talk in radians.  One complete revolution is an angle of 2π radians.

Minute hand speed:  2π radian/hour

Speed = (2π/hr) x (1 hr/3600 sec)

Speed = 2π/3600 sec

Speed = 1.75 x 10⁻³ radian/sec

Speed = 0.1 degree/sec

Hour hand speed = 2π / 12 hours = π/6 radian per hour

Speed = (π / 6 hour) x (1 hour / 3600 sec)

Speed = 1.45 x 10⁻⁴ radian/sec

Speed = 30 degrees/hour

Speed = 8.3 x 10⁻³ degree/second

The angular speed of the minute hand of a clock is 2π rad/hour, and for the hour hand, it’s 2π rad/12 hours. This calculation comes from dividing the total rotation angle (2π rad) by the time it takes to complete that rotation. This utilizes the principles of rotational motion in Physics.

To find the angular speed of the minute and hour hand on a clock, a concept from Physics, specifically rotational motion, is applied. The angular speed is defined as the change in angle per unit time. In a clock, a complete rotation, which is equal to 360° or 2π radians, takes an hour for the minute hand and 12 hours for the hour hand.

For the minute hand: it completes one rotation (360° or 2π radians) in 60 minutes (1 hour). So, its angular speed ω is equal to the total angle θ divided by the total time t: ω (minute) = θ / t = 2π / 1 hour.

For the hour hand: it completes one rotation in 12 hours. Hence, its angular speed is: ω (hour) = θ / t = 2π / 12 hours.

Please note that this calculation considers a simple ideal case. In real life scenarios, factors such as mechanism quality, temperature, even relativistic effects if the clock moves very fast, like the satellite clocks, can cause slight differences.

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Explanation:

The frequency of a spring is:

f = 1/(2pi) sqrt(k / m)

If m doubles, then f decreases by a factor of 1/sqrt(2).

Doubling the mass attached to a spring in a frictionless simple harmonic oscillator will decrease the frequency of oscillation by a factor of √2, or approximately 0.7071 times the original frequency.

In a simple harmonic oscillator like the mass-spring system described, the frequency of oscillation is given by f = (1/2π) * √(k/m), where k represents the spring constant and m the mass attached to the spring. If the mass is doubled, the frequency of the oscillation will decrease because the frequency is inversely proportional to the square root of the mass. Therefore, if the mass increases by a factor of two, the new frequency will be f' = (1/2π) * √(k/2m), which is f' = f/√2. This implies that the frequency will decrease by a factor of √2, or approximately 0.7071 times the original frequency.

Answer:

10.2 atm

Explanation:

Use ideal gas law:

PV = nRT

Initial number of moles is:

(2.20 atm) (0.859 L) = n (0.0821 atm L / mol / K) (565 K)

n = 0.0407 mol

At the new volume and temperature, the pressure is:

P (0.268 L) = (0.0407 mol) (0.0821 atm L / mol / K) (815 K)

P = 10.2 atm

We have that the pressure the sample have if the volume changes to 268 ml while the temperature is increased to 815 k is

[tex]P_2=10atm[/tex]

From the question we are told

A sample of gas initially has a volume of 859 ml at 565 k and 2.20 atm. What pressure will the sample have if the volume changes to 268 ml while the temperature is increased to 815 k

Generally the equation for the ideal gas   is mathematically given as

PV=nRT

Where

[tex]\frac{P1V1}{T1}=\frac{P2V2}{T2}[/tex]

Therefore

[tex]P_2=\frac{P1V1T2}{V2T1}\\\\P_2=\frac{2.20*859*815}{268*565}[/tex]

[tex]P_2=10atm[/tex]

THEREFORE

the pressure the sample have if the volume changes to 268 ml while the temperature is increased to 815 k is

[tex]P_2=10atm[/tex]

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Answer:

The direction of the magnetic force acting on a current-carrying wire in a uniform magnetic field is perpendicular to the direction of the field.

The direction of the magnetic force acting on a current-carrying wire in a uniform magnetic field is perpendicular to the direction of the current.

The magnetic force on the current-carrying wire is strongest when the current is perpendicular to the magnetic field lines.

Explanation:

The magnitude of the magnetic force exerted on a current-carrying wire due to a magnetic field is given by

[tex]F=ILB sin \theta[/tex] (1)

where I is the current, L the length of the wire, B the strength of the magnetic field, [tex]\theta[/tex] the angle between the direction of the field and the direction of the current.

Also, B, I and F in the formula are all perpendicular to each other. (2)

According to eq.(1), we see that the statement:

"The magnetic force on the current-carrying wire is strongest when the current is perpendicular to the magnetic field lines."

is correct, because when the current is perpendicular to the magnetic field, [tex]\theta=90^{\circ}, sin \theta = 1[/tex] and the force is maximum.

Moreover, according to (2), we also see that the statements

"The direction of the magnetic force acting on a current-carrying wire in a uniform magnetic field is perpendicular to the direction of the field. "

"The direction of the magnetic force acting on a current-carrying wire in a uniform magnetic field is perpendicular to the direction of the current. "

because F (the force) is perpendicular to both the magnetic field and the current.

The magnetic force on a current-carrying wire in a uniform magnetic field is perpendicular to both the magnetic field lines and the direction of the current. The force is strongest when the current is perpendicular to the magnetic field lines, and is zero when the current runs parallel to the magnetic field lines.

According to the principles of magnetism and the right-hand rule, the magnetic force acting on a current-carrying wire in a uniform magnetic field is perpendicular to both the magnetic field and to the current direction. The strength of the magnetic force on the wire is dictated by the equation F = I x B, where F is the force, I represents the current, and B is the strength of the magnetic field.

When the current flows parallel to the magnetic field lines, the force experienced by the wire is actually zero due to the nature of the cross product in the force formula. However, the magnetic force on the current-carrying wire is strongest when the current is perpendicular to the magnetic field lines. This is because the effect of the magnetic force is most significant when these two quantities are at right angles to each other.

In terms of the direction of the force, you can use the right-hand rule. If you point your thumb in the direction of the current, and your fingers in the direction of the magnetic field, your palm will point in the direction of the force on the wire.

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Answer:

converting that mass to energy by using E=mc2. Mass must be in units of kg. Once this energy, which is a quantity of joules for one nucleus, is known, it can be scaled into per-nucleon and per-mole quantities.

Explanation:

Answer:

An elephants balls

Explanation:

Answer:

They experience the same magnitude impulse

Explanation:

We have a ping-pong ball colliding with a stationary bowling ball. According to the law of conservation of momentum, we have that the total momentum before and after the collision must be conserved:

[tex]p_i = p_f\\p_p + p_b = p'_p+p'_b[/tex]

where

[tex]p_p[/tex] is the initial momentum of the ping-poll ball

[tex]p_b[/tex] is the initial momentum of the bowling ball (which is zero, since the ball is stationary)

[tex]p'_p[/tex] is the final momentum of the ping-poll ball

[tex]p'_f[/tex] is the final momentum of the bowling ball

We can re-arrange the equation as follows

[tex]p_p - p'_p = p_b'-p_b[/tex]

or

[tex]-\Delta p_p = \Delta p_b[/tex]

which means

[tex]|\Delta p_p | = |\Delta p_b|[/tex] (1)

so the magnitude of the change in momentum of the ping-pong ball is equal to the magnitude of the change in momentum of the bowling ball.

However, we also know that the magnitude of the impulse on an object is equal to the change of momentum of the object:

[tex]I=\Delta p[/tex] (2)

Therefore, (1)+(2) tells us that the ping-pong ball and the bowling ball experiences the same magnitude impulse:

[tex]|I_p| = |I_b|[/tex]

Answer:

45 V

Explanation:

Use Ohm's law:

V = IR

V = (3.0 A) (15 Ω)

V = 45 V

Answer:

45V

Explanation:

R=V/I

V=I/R

V=15ohms•3.0 A

V=45V

Answer:

e.)At twice the distance, the strength of the field is E/4.

Explanation:

The strength of the electric field at a certain distance from a point charge is given by:

[tex]E=k\frac{Q}{r^2}[/tex]

where

k is the Coulomb's constant

Q is the charge

r is the distance from the point charge

In this problem, the distance from the point charge is doubled:

r' = 2r

So the new electric field strength is

[tex]E'=k\frac{Q}{(2r)^2}=k \frac{Q}{4 r^2}=\frac{1}{4} (k\frac{Q}{r^2})=\frac{E}{4}[/tex]

so, at twice the distance the strength of the field is E/4.

The strength of the electric field at twice the distance from a point charge is one-fourth of its original strength. So the correct option is (e).

The strength of the electric field at a certain distance from a point charge is generally given by the formula E = k|Q|/r², where k is Coulomb's constant, Q is the magnitude of the charge, and r is the distance from the charge to the point in question. When the distance is doubled (2r), the formula becomes E' = k|Q|/(2r)², which simplifies to E' = E/4. Therefore, the strength of the electric field at twice the distance from the point charge is one-fourth the original strength.

Answer:

d. Potential energy is converted to kinetic energy; the kinetic energy is then converted into the work of bringing the body to a stop

Explanation:

- When the person starts his/her fall from a certain height h, he/she possesses gravitational potential energy:

[tex]U=mgh[/tex]

where m is the mass of the person, g is the acceleration due to gravity, h is the height.

- During the fall, the height h decreases, while the speed of the person increases, so gravitational potential energy is converted into kinetic energy:

[tex]K=\frac{1}{2}mv^2[/tex]

where

m is the mass of the person

v is the speed

- Just a moment before hitting the ground, h=0, so all the potential energy has been converted into kinetic energy

- When the person hits the ground, he/she comes a stop: this means that now the speed is zero (v=0), so the kinetic energy is zero as well. This occurs because all the kinetic energy has been converted into the work of bringing the body to a stop. (the work has been done by the ground on the person)

During a phase change, the temperature of a substance (c). stays the same.

The temperature remains same during the phase change.

Answer: Option C

Explanation:

The term “change of phase” is similar to “change of state”. When there is a change of substance from a state to the other state or phase, it is known as changes in its state. This change of state occurs due to the change of heat.

When a substance changes the phase, either the heat comes out or goes in the substance. Although there occur a change in the content of heat present in the substance, the temperature will not change. It remains constant.  When ice melts it becomes water and the water vaporizes which becomes water vapour.