1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Spring force on car

  1. May 18, 2012 #1
    1. The problem statement, all variables and given/known data

    To test the resiliency of its bumper during low-speed collisions, a 4 600-kg automobile is driven into a brick wall. The car's bumper behaves like a spring with a force constant 8.00 106 N/m and compresses 3.36 cm as the car is brought to rest. What was the speed of the car before impact, assuming no mechanical energy is transformed or transferred away during impact with the wall?

    2. Relevant equations

    3. The attempt at a solution







    = √(((0.0336)(1.12896*10-3))/4600)

    v= 1.4 m/s is this correct it seemed a little slow for a car?
  2. jcsd
  3. May 18, 2012 #2


    User Avatar
    Science Advisor
    Homework Helper
    Gold Member

    Looks good! Don't forget that if the car was going fast, the bumper would compress more than a mere 3 cm. Good thing it was going slow!
  4. May 18, 2012 #3
    Thanks Phantom Jay.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook