law of conservation

Question

A 6.00 ✕ 10⁵ kg subway train is brought to a stop from a speed of 0.500 m/s in 0.800 m by a large spring bumper at the end of its track. What is the force constant k of the spring (in N/m)? (need a number)

Answer 1

The kinetic energy of the train transferred to elastic potential energy. delta KE=1/2 KX square.

1/2 m(vfinal square- v initial square) = 1/2 Kx square.

x=0.800 m,v i = 5.00 m/s ,v f = 0 m/s .