Anonymous
Anonymous asked in Cars & TransportationOther - Cars & Transportation · 1 decade ago

Kinetic energy?

A 1500 kg car is traveling 30 m/s along a horizontal road when the brakes are applied. The car skids to a stop in 4 s. How much kinetic energy ( in J) does the car lose in this time ?

Update:

Physics Question ?? HELP

10 Answers

Relevance
  • ndtaya
    Lv 6
    1 decade ago
    Favorite Answer

    No idea. I have always regretted not taking physics.

    • Commenter avatarLogin to reply the answers
  • 1 decade ago

    If the car comes to a complete stop, then it should have lost all of its kinetic energy.

    So as the car was moving, it had

    1/2 m v^2

    (1/2)(1500)(30)^2 = 675,000 J

    The time seems to be in there just to throw you off, if the question is asking how much KE the car lost (it ends up with none).

    • Commenter avatarLogin to reply the answers
  • 1 decade ago

    Kinetic energy is the energy that a body possesses as a result of its motion. It is formally defined as the work needed to accelerate a body from rest to its current velocity. Having gained this energy during its acceleration, the body maintains this kinetic energy unless its speed changes. Negative work of the same magnitude would be required to return the body to a state of rest from that velocity.

    Source(s): wikipedia.org
    • Commenter avatarLogin to reply the answers
  • jaji
    Lv 4
    4 years ago

    surely thermal ability is kinetic temperature is the degree of the established kinetic ability of the debris in a pattern yet there is also ability ability it really is ability linked with position or some subject an merchandise sitting on a table has ability ability with respect to the floor yet there is not any action if the article falls, then that ability ability is switched over to kinetic chemical bonds have ability ability it really is each and every from time to time switched over to kinetic (mostly contained in the kind of thermal ability) as even as a gas which includes methane is burned the debris contained in the nucleus of an atom have ability ability which will properly be switched over to kinetic (in various of circumstances thermal) ability even as the debris are rearranged as in fission or fusion of nuclei

    • Commenter avatarLogin to reply the answers
  • How do you think about the answers? You can sign in to vote the answer.
  • 1 decade ago

    KE=1/2mv^2

    KE=1/2(1500)(30^2)

    KE=675000J

    its asking how much KE is lost, so if its at stop then it lost all its energy so KE=0 at the end of the 4s

    i think the time is there to get people confused

    • Commenter avatarLogin to reply the answers
  • 1 decade ago

    Not sure if this is in joules or not

    Ke=W*V2/64.4

    Ke=3306.93*98.43 squared/64.4

    Ke=3306.93*9688.4649/64.4

    Ke=32039075.23/64.4

    Ke=497501.1682

    The amount of time is meaningless because the vehicle skidded to a stop and there fore lost all of its kinetic energy during the four seconds.

    Note: I had to change m/s into f/s and kg into lbs.

    Source(s): Traffic Crash Reconstructionist
    • Commenter avatarLogin to reply the answers
  • Anonymous
    1 decade ago

    I think it's(1500 x 30)-4 but I'm not sure.

    • Commenter avatarLogin to reply the answers
  • Anonymous
    1 decade ago

    Isn't that potential energy? I have no idea, my brother is learning that but he doesn't learn during class. Sorry no idea, ask in askjeeves.com?

    • Commenter avatarLogin to reply the answers
  • 1 decade ago

    geeze just ask your teacher if you are having problems with your homework.....

    • Commenter avatarLogin to reply the answers
  • 1 decade ago

    I HATE PHYSICS!!!!!!!!!!!!!!

    • Commenter avatarLogin to reply the answers
Still have questions? Get your answers by asking now.