A 1000 kg car moving at 108 km/h jams on its brakes and comes to a stop. How much work was done by friction?

Answers

Answer 1

Answer:

The work done by friction was [tex]-4.5\times10^{5}\ J[/tex]

Explanation:

Given that,

Mass of car = 1000 kg

Initial speed of car =108 km/h =30 m/s

When the car is stop by brakes.

Then, final speed of car will be zero.

We need to calculate the work done by friction

Using formula of work done

[tex]W=\Delta KE[/tex]

[tex]W=K.E_{f}-K.E_{i}[/tex]

[tex]W=\dfrac{1}{2}mv_{f}^2-\dfrac{1}{2}mv_{f}^2[/tex]

Put the value of m and v

[tex]W=0-\dfrac{1}{2}\times1000\times(30)^2[/tex]

[tex]W=-450000 \ J[/tex]

[tex]W=-4.5\times10^{5}\ J[/tex]

Hence, The work done by friction was [tex]-4.5\times10^{5}\ J[/tex]


Related Questions

PLEASE HELP ME 20 POINTS Some metals have a molecular structure that makes them good conductors. Explain how understanding this relationship can help engineers make more powerful batteries.

PLEASE I KNOW THE STRUCTURE I JUST NEED HOW BY UNDERSTANDING THE RELATIONSHIP THEY CAN MAKE MORE POWERFUL BATTERIES.

PLEASE IM DYEING HERE I JUST NEED THIS ANSWER I WILL GIVE BRAINLIST AND 5 STARS A HEART WHATEVER JUST PLEASEEEEE.

Answers

Answer:

negative plus positive with energy = battery

Explanation:

which one of the following is a correct statement......

1)increasing temperature will decrease a pressure of gas

2)increase in amount of gas will decrease the pressure of gas

3)increasing the volume of gas will decrease the pressure of gas

4)all of the above​

Answers

Answer:

Just 3

Explanation:

I believe the other two are incorrect

What is a
physical
property of
snowflakes?

Answers

The shape of the snowflake is determined broadly by the temperature and humidity at which it is formed. Rarely, at a temperature of around −2 °C (28 °F), snowflakes can form in threefold symmetry — triangular snowflakes. Most snow particles are irregular in form, despite their common depiction as symmetrical.

a body of mass 1kg is made to oscillate on a spring of force constant 16 n/m calculate 1 the angular frequency 2 the frequency of oscillation

Answers

Explanation:

Given that,

Mass of a body, m = 1 kg

Force constant, k = 16 N/m

We need to find the angular frequency and the frequency of oscillation.

(a) The angular frequency of a body is given by :

[tex]\omega=\sqrt{\dfrac{k}{m}} \\\\=\omega=\sqrt{\dfrac{16}{1}} \\\\=4\ rad/s[/tex]

(b) The frequency of oscillation is given by :

[tex]f=\dfrac{\omega}{2\pi}\\\\f=\dfrac{4}{2\pi}\\\\=\dfrac{2}{\pi}\ Hz[/tex]

Hence, this is the required solution.

A 2.0 kg mass on a horizontal spring is pulled back 2.0 cm and released. If, instead, a 0.40 kg mass were used in this same experiment, the total energy of the system would: ________

a. Remain the same.
b. Double.
c. Be half as large.

Answers

Answer:

a. Remain the same.

Explanation:

The total energy of the spring mass system is given as

[tex]$E=\frac{1}{2}kx^2 $[/tex]

where k is the spring constant of the spring

           x is the compression or expansion of the spring

The energy of the spring mass system is always independent of mass. It does not depends on the mass object attached to the spring.

Therefore, the total energy of the system will remain the same in the experiment when the mass is changes the second time.

Engineers are developing a process to produce phosphorus pentachloride.
Which two criteria are the most essential when developing this process?

Answers

Answer:

The two criteria that are most essential are options C and D

Explanation:

In trying to develop a new process/procedure for the commercial/industrial production of a particular substance (in this case phosphorus pentachloride), it is important that the workers that would operate the equipment required for this new procedure are able to operate it safely, i.e without fear of injury or losing one's life. If this fear is present or any adverse effect occurs, it would not only be counterproductive but would also make workers avoid using this procedure and may be forced to revert to previous safe procedure.

It is also essential for the new procedure to be able to get the most desired product out of the reactant, meaning the rate and amount of desired product (phosphorus pentachloride) that would be obtained from a given amount of reactant must be very high (a better upgrade when compared to the previous procedure). This is going to cause for a better amount of phosphorus pentachloride produced as against the previous amounts produced from previous procedure.

From the above, it can be deduced that options C and D are two criteria that are most essential when trying to develop a novel process to produce phosphorus pentachloride.

Answer: the guy above me is correct

Explanation:

Balboa Park in San Diego has an outdoor organ. When the air temperature increases, how does the fundamental frequency of the one of the organ pipes change?

a. increases
b. decreases
c. stays the same
d. is impossible to determine. (The thermal expansion of the pipe is negligible.)

Answers

Answer:

a. increases

Explanation:

Outdoor pipe organ is a musical instrument that is used to play music. It produces some soothing notes and is very peaceful to the ears. The organ pipe is the source of sound for the outdoor organ. And the length of the pipe determines the wavelength of the sound. When the air temperature of the surrounding is increased, the fundamental frequency of one of the organ pipes will be increased as the speed of the sound will increased.

Suppose that you take a 10 kg mass on the surface of the earth and then place it on the moon. What will
the mass of the object on the moon be?

Answers

Answer:

10 kg

Explanation:

The mass of an object does not change even if the amount of gravtiy changes.

Plants that respond to light are responding
to an:
a. internal stimulus
b. external stimulus

please answer

Answers

i believe the answer is b. external stimulus

Answer:

The answer would be a

Explanation:

Please HElp!!

Name five conductors and insulators

Answers

Answer:

Conductors- copper, aluminum, gold, and silver.

Insulators- glass, air, plastic, rubber, and wood.

Explanation:

Answer: 5 conductors are copper, aluminum, gold, iron, and silver and 5 insulators are glass, air, plastic, rubber, and wood.

1) Andrea and Chuck are riding on a merry-go-round. Andrea rides on a horse at the outer rim of the circular platform, twice as far from the center of the circular platform as Chuck, who rides on an inner horse. When the merry-go-round is rotating at a constant angular speed, Andrea's tangential speed is which of the following?a) twice Chuck's.b) the same as Chuck's.c) half of Chuck's.d) impossible to determine.2) When the merry go round is rotating at a constant angular speed, Andrea's tangential speed is:______.a) twice Chuck's.b) the same as Chuck's.c) half of Chuck's.d) impossible to determine.

Answers

Explanation:

The tangential speed of Andrea is given by :

[tex]v=r\omega[/tex]

Where

r is radius of the circular path

ω is angular speed

The merry-go-round is rotating at a constant angular speed. Let the new distance from the center of the circular platform is r'

r' = 2r

New angular speed,

[tex]v'=r'\omega'\\\\v'=(2r)\omega\\\\v'=2r\omega\\\\v'=2v[/tex]

New angular speed is twice that of the Chuck's speed.

Select the correct answer.
What are the units for the spring constant, k?
OA newton meters
OB. newton seconds
OC. newtons/meter
OD. newtons/second
E. newtons/seconds

Answers

I think D ? Is the answer
The correct answer is C

A baseball player slides into home base and experiences coefficients of friction of μ8 = 0.63 and μk = 0.49. The normal force acting on the player is 660N. How much frictional force acts on the player?Round your answer to the nearest hundredth if necessary. Ff = ________ N

Answers

Answer:

323.4 N

Explanation:

Given that,

The coefficient of static friction, [tex]\mu_s=0.63[/tex]

The coefficient of kinetic friction, [tex]\mu_k=0.49[/tex]

We need to find the frictional force acting on the player. As the baseball player is sliding into home base, we will use the coefficient of kinetic friction to find the frictional force.

[tex]F=\mu _kN\\\\=0.49\times 660\\\\=323.4\ N[/tex]

So, the frictional force acting on the player is 323.4 N.

How can music imitate nature?​

Answers

How it is played could be a way

Answer:

There are at least two ways contemporary music in America has made use of nature by directly making use of the sounds of nature as musical material, or else in works that desire to imitate nature "in its manner of operation." That is, they are constructed the way nature is, they work the way nature works, rather than sounding the way nature sounds.

Explanation:

A tiny water droplet of radius . descends through air from a high building.
Calculate its terminal velocity. Given that for air = × − −− and density of the water = -3

Answers

Correct question is;

A tiny water droplet of radius 0.010 cm descends through air from a high building .Calculate its terminal velocity . Given that η of air = 19 × 10^(-6) kg/m.s and density of water ρ = 1000kg/ms

Answer:

1.146 m/s

Explanation:

We are given;

Radius; r = 0.010 cm = 0.01 × 10^(-2) m

η = 19 × 10^(-6) kg/m.s

ρ = 1000 kg/ms

The formula for the terminal velocity is given by;

V_t = 2r²ρg/9η

g is acceleration due to gravity = 9.8 m/s²

Thus;

V_t = (2 × (0.01 × 10^(-2))² × 1000 × 9.8)/(9 × 19 × 10^(-6))

V_t = 1.146 m/s

In general, how did the water pressure in the tank change when mass was added to the fluid?

Answers

Answer:

As the height increases the pressure must increase.

Explanation:

When we add masses to the fluid, the amount of fluid in the tank increases, therefore its height increases and the pressure is described by the expression

           P = ρ g h

where rho is constant for a given fluid and h is the height measured from the surface of the fluid.

As the height increases the pressure must increase.

Nose bleeding occurs as we move towards high altitude, why?

Answers

Nosebleeds can be caused by being up in a very high altitude. As you climb higher, the amount of oxygen in the air decreases. This makes the air thinner and dryer, which can in turn cause the inside of your nose to crack and bleed.F

Answer:

Because as we climb higher the amount of oxygen in the air decreases and this makes the air thinner and dryer. And at higher altitudes the blood pressure inside of our body is more than the atmospheric pressure which forces the blood to come out from openings like the nose.

Explanation:

it takes 10 J of energy to move 2 C of charge from point A to point B. How large is the potential difference between points A and B

Answers

Ok so what we need to find is how large is the potential difference between points A and B.

Now you make a statement about what this potential difference would do in this problem

We now know that the points from A and B relies to transport a difference by using points A to B per unit change.

V
=
W/
q
=
50/
10
=
5
V=
q
W

=
10
50

=5 V (5 volt).

Given the workdone and the quantity of the charge, the potential difference between points A and points B is 5 Volts.

What is potential difference?

Potential difference is simply referred to as work done required to move a charge from point A to point B per unit charge.

It is expressed as;

V = W / q

Given the data in the question;

Work done W = 10JQuantity of charge q = 2CPotential difference V = ?

We substitute our values into the exression above.

V = W / q

V = 10J / 2C

V = 5V

Therefore, given the workdone and the quantity of the charge, the potential difference between points A and points B is 5 Volts.

Learn more about potential difference here: https://brainly.com/question/23716417?referrer=searchResult

#SPJ2

How is a mesa formed

Answers

Mesas form by weathering and erosion of horizontally layered rocks that have been uplifted by tectonic activity. Variations in the ability of different types of rock to resist weathering and erosion cause the weaker types of rocks to be eroded away, leaving the more resistant types of rocks topographically higher than their surroundings. This process is called differential erosion. 

Hope it helps!

Mesas are formed by erosion, when water washes smaller and softer types of rocks away from the top of a hill. The strong, durable rock that remains on top of a mesa is called caprock. A mesa is usually wider than it is tall.

The maximum value of the electric field in an electromagnetic wave is 2.0 V/m. What is the maximum value of the magnetic field in that wave

Answers

Answer:

The maximum value of the magnetic field in the given wave is 6.67 nT.

Explanation:

Given;

maximum value of the electric field, E₀ = 2.0 V/m

The maximum value of the magnetic field in the given wave is calculated as;

[tex]B_o = \frac{E_o}{c}[/tex]

where;

c is the speed of light = 3 x 10⁸ m/s

[tex]B_o = \frac{E_o}{c} \\\\B_o = \frac{2}{3 \ \times \ 10^8} \\\\B_o = 6.67 \ \times \ 10^{-9} \ T\\\\B_o = 6.67 \ nT[/tex]

Therefore, the maximum value of the magnetic field in the given wave is 6.67 nT.

A proton with an initial speed of 600,000 m/s is brought to rest by an electric field.1. What was the potential difference that stopped the proton?
2. What was the initial kinetic energy of the proton, in electron volts?

Answers

Answer:

(1) the potential difference that stopped the proton is 1878.75 V

(2) the initial kinetic energy of the proton is 1878.75 eV

Explanation:

Given;

initial speed of the proton, v = 600,000 m/s

mass of proton, m = 1.67 x 10⁻²⁷ kg

(1) The work done in bringing the proton to rest is given as;

[tex]W = eV[/tex]

Apply work energy theorem;

[tex]K.E =W\\\\ \frac{1}{2} mv^2 = eV\\\\V = \frac{mv^2}{2e}[/tex]

where;

V is the potential difference

[tex]V = \frac{1.67\times 10^{-27} \times\ 600,000^2}{2 \ \times \ 1.6 \times 10^{-19}} \\\\V = 1878.75 \ V[/tex]

(2) the initial kinetic energy of the proton, in electron volts;

[tex]K.E = \frac{1}{2} mv^2\\\\K.E = \frac{1}{2} \times \ 1.67\times 10^{-27} \times 600,000^2 = 3.006 \times 10^{-16} \ J\\\\K.E = \frac{3.006 \times 10^{-16} \ J \ \ eV}{1.6 \times 10^{-19} \ J} = 1878.75 \ eV[/tex]

a body is pulled through a distance of 500m by a force of 20N. if the power developed is 0.4KW, calculate the time for which the force act?​

Answers

Answer:

25000N

Explanation:

distance travelled(d)=500m

force(f)=20N

Power=0.4KW=0.4×1000Watt=400watt

Then,Time(T)=?

Now,

Power(P)=W/T

400=F×D/T.(w=f×d)

or, 400=20×500/T

or, 400=10000/T

or, T=10000/400

or,T=25 sec

Therefore,time taken=25 sec

why was bowling one of the first racially integrated sports

Answers

Answer:

bowling was one of the first racially integrated sports because bowling alleys were primarily located in urban areas. Racial integration was inevitable since it was promoted by US Armed Forces during 1940s and its image as sport for the common man made it a choice of activity for Americans!!

Explanation:

Deduce the first
equation
of motion matematical method​

Answers

Answer:

The answer is below

Explanation:

Equation of motion is a term in physics that is used in explaining the characteristics of a physical system concerning its motion while considering the period.

The First Equation of Motion is given as v = u + at

Here, a = acceleration, v = final velocity, u = initial velocity, and t = time

To deduce it algebraically, it is written as

a = (v - u) ÷ t

Therefore, it can be repositioned to => v = u + a * t

What does a sound wave’s frequency tell you?
a - the number of vibrations per second an object is making
b - the loudness or softness of the sound from an object
c - the amplitude of the sound wave
d - the type of medium in which the sound is traveling

Answers

Answer:

The number of vibrations per second an object is making

Explanation:

We need to find the correct option for a sound wave’s frequency.

Frequency is the number of vibrations per second an object is making. It can be calculated as total no. of vibrations divided by time taken.

Its SI unit is Hertz and it is denoted by Hz.

Hence, the correct option is (a).

1) A 40 kg girl gets on her 10 kg wagon on level ground with two 5 kg bricks. She throws the bricks horizontally off the back of the wagon one at a time at a speed of 7 m/s relative to herself. a) How fast does she go after throwing the second brick

Answers

Answer:

1.4 m/s

Explanation:

Assuming that the system is an isolated one, then we will conserve the linear momentum of the system so as to be able to solve the system for required quantities:

Using the conservation of momentum, we have,

initial momentum = final momentum

P(i) = P(f)

And from the question, we see that the system has no initial momentum

After throwing the first brick we have

(40 + 10 + 5)v2 + 5 * -7 = 0

55v2 - 35 = 0

55v2 = 35

v2 = 35/55

v2 = 0.63 m/s

Now, considering that she conserves momentum when she throws the second brick again, we then say

(40 + 10 + 5) * 0.63 = (40 + 10)v(f) + 5 * -7

55 * 0.63 = 50v(f) - 35

35 = 50v(f) - 35

50v(f) = 35 + 35

50v(f) = 70

v(f) = 70/50

v(f) = 1.4 m/s

The 1kg rock is tied to a string and swung in a circular path as shown. The 1 meter string is tied to a post, and during the motion, the string has a 30 angle with the post. The rock makes 100 rounds in 1 minute. The centripetal force on the rock is

Answers

Answer: 54.8

Explanation:

The centripetal force on the rock moving along the string is 104.66 N.

The given parameters;

the mass of the rock, m = 1 kgangle of inclination of the string, θ = 30⁰angular velocity of the rock, ω = 100 rev/minlength of the string, r = 1 m

The centripetal acceleration of the rock is calculated as follows;

[tex]\omega _f^2 = \omega _i^2 + 2\alpha (\theta)\\\\(100 \ \frac{rev}{\min} \times \frac{2\pi \ rad}{1 \ rev} \times \frac{1 \min}{60 \ s} )^2 = 0 + 2\alpha (30 ^0 \times \frac{\pi \ rad}{180^0} )\\\\109.69 = 1.048\alpha \\\\\alpha = \frac{109.69}{1.048} \\\\\alpha =104.66 \ rad/s^2[/tex]

[tex]a_c = \alpha \times r\\\\a_c = 104.66 \times 1 = 104.66 \ m/s^2[/tex]

The centripetal force on the rock is calculated as follows;

[tex]F_c = ma_c[/tex]

[tex]F_c = 104.66 \times 1\\\\F_c = 104.66 \ N[/tex]

Thus, the centripetal force on the rock moving along the string is 104.66 N.

Learn more here: https://brainly.com/question/20905151

Which of the following is a correct equation for total energy?
Total energy = Kinetic energy / potential energy
Total energy = Kinetic energy - potential energy
Total energy = Kinetic energy * potential energy
Total energy = Kinetic energy + potential energy

Answers

Answer:

kinetic energy + potential energy

Answer:

D is the correct answer: Total energy = Kinetic energy + potential energy

A ball is thrown straight up in the air. For which situations are both the instantaneous velocity and the acceleration zero?

a. on the way up
b. at the top of its flight path
c. on the way down
d. halfway up and halfway down
e. none of the above

Answers

Answer: e: none of the above.

Explanation:

For any object in the air, the gravitational acceleration will be always -9.8m/s^2, where the negative sign is because gravity pulls the object down.

The instantaneous velocity, as a function of time, for the case of the ball, is

V(t) = (-9.8m/s^2)*t + v0

Where v0 is the velocity at which the ball is thrown up.

The velocity will be zero when the ball is at the top of its flight pat, in that point the sign of the velocity changes, it stops being positive (so the ball stops going up) and becomes negative (so the ball starts to fall down).

Now, while the instantaneous velocity can be zero during the flight, the acceleration does not, it only will be zero when the object hits the ground. Then the only correct option will be e: none of the above.

Does the air in a room or water in a pot have to be at a certain temperature to create convection? Yes or No? and Explain why?

Answers

Answer:

Yes

Explanation:

because that temperature creates the bulk movement of molecules due to increase in their kinetic energy

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