Question

A 81 kg block is released at a 3.8 m height. the track is frictionless. the block travels down the track, hits a massless spring constant k=1888.calculate the average force

Answer 1

Since the track is friction less, block’s kinetic energy at the bottom of the track is equal to its potential energy at the top of the track. 
PE = 81 * 9.8 * 3.8 = 3016.44 J
 Work = 1/2 * 1888 * d^2  
PE = Kinetic energy at the base.
 1/2 * 1888 * d^2 = 3016.44
 d = 1.78 approx 1.8
 F = Ke = 1888 * 1.8 = 3398.4N