posted by James .
In a railroad yard, a 2.0×104 kg boxcar moving at 10m/s is brought to a stop by a spring-loaded bumper mounted at the end of the level track.
If the spring constant 1.7 MN/m , how far does it compress in stopping the boxcar?
What do i do?
kinetic energy lost = (1/2) m v^2
potential energy gained = (1/2) k x^2