1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
yulyashka [42]
3 years ago
10

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?

Physics
1 answer:
Nostrana [21]3 years ago
3 0

Answer:

The work done by friction was -4.5\times10^{5}\ J

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

W=\Delta KE

W=K.E_{f}-K.E_{i}

W=\dfrac{1}{2}mv_{f}^2-\dfrac{1}{2}mv_{f}^2

Put the value of m and v

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

W=-450000
\ J

W=-4.5\times10^{5}\ J

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

You might be interested in
What is the most dense thing in the world
Mashcka [7]
Any lump of osmium is. Iridium and gold are also very close.
7 0
3 years ago
Read 2 more answers
A rock is thrown vertically upward from some height above the ground. It rises to some maximum height and falls back to the grou
True [87]

Answer:

At the highest point the velocity is zero, the acceleration is directed downward.

Explanation:

This is a free-fall problem, in the case of something being thrown or dropped, the acceleration is equal to -gravity, so -9.80m/s^2. So, the acceleration is never 0 here.

I attached an image from my lecture today, I find it to be helpful. You can see that because of gravity the acceleration is pulled downwards.

At the highest point the velocity is 0, but it's changing direction and that's why there's still an acceleration there.

6 0
3 years ago
A proton is 0.9 meters away from a 1.4 C charge. What is the magnitude of the electric force between the proton and the charge
Digiron [165]

Answer:

F = 2.49 x 10⁻⁹ N

Explanation:

The electrostatic force between two charged bodies is given by Colomb's Law:

F = \frac{kq_1q_2}{r^2}\\

where,

F = Electrostatic Force = ?

k = colomb's constant = 9 x 10⁹ N.m²/C²

q₁ = charge on proton = 1.6 x 10⁻¹⁹ C

q₂ = second charge = 1.4 C

r = distace between charges = 0.9 m

Therefore,

F = \frac{(9\ x\ 10^9\ N.m^2/C^2)(1.6\ x\ 10^{-19}\ C)(1.4\ C)}{(0.9\ m)^2}

<u>F = 2.49 x 10⁻⁹ N</u>

8 0
3 years ago
Read 2 more answers
PLEASE IM TIMED! GIVE BRAINLIEST OF U ANSWER THESE 2 QUESTION!!
erastovalidia [21]

Answer:

  • thermal
  • true

Explanation:

hope this helps!

7 0
3 years ago
Read 2 more answers
Determine tge energy in joules of a photon whose frequency is 3.55x10
JulijaS [17]
E = hf
E = 6.63×10^-34 × 3.55×10 eV
1 eV = 1.60×10^-19 J
E = 6.63×10^-34 × 3.55×10 × 1.60×10^-19
E = 3.77×10^-51 J

Hope it helped!
6 0
3 years ago
Other questions:
  • To distinguish between properties of the two major types of supernovae: massive star supernovae and white dwarf supernovae. all
    9·1 answer
  • A wave has a distance between its peaks of 0.4 meters at a speed of 10 meters per second. What is the wave's frequency, in hertz
    11·1 answer
  • The light intensity incident on a metallic surface with a work function of 3 eV produces photoelectrons with a maximum kinetic e
    10·1 answer
  • Complete the blanks and tell the reaction force
    8·1 answer
  • A light plane must reach a speed of 33m/s for takeoff.how long a runway is needed if the the acceleration is 3.0m/s^2
    9·1 answer
  • How long does it take to raise the temperature of the air in a good-sized living room (3.00m×5.00m×8.00m) by 10.0∘C? Note that t
    10·1 answer
  • How physical properties are important for identifying unknown substances
    13·1 answer
  • A construction worker uses an electrical device to attract fallen nails and sharp objects
    10·1 answer
  • Why do I hear a loud sound when I put my ear against the wall and knock
    14·1 answer
  • When a parachutist jumps from an airplane, he eventually reaches a constant speed, called the terminal speed. Once he has reache
    15·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!