1. The problem statement, all variables and given/known data 2. Relevant equations KE = 1/2mv^2 f = -kx U = 1/2kx^2 Kinematic equations F = ma 3. The attempt at a solution Horizontal components of the block's weight: 8.38N Compression of the spring: f = -kx 8.37 = -500x x = 0.01674 m , which is wrong and I would be grateful if someone can explain to me why it is wrong Then, I changed the approach Find the acceleration of the block F= ma 8.37 = 2.5a a = 3.348 ms^-2 u = 0.75, v = ?, a = 3.348, s = 0.3 v^2 = u^2 + 2as v^2 = 0.75^2 + 2(3.348)(0.3) v = 1.603 m/s W = KE change when the blocj hit the spring W = 1/2(2.5)(1.603)^2 - 1/2(2.5)(0)^2 W = 3.212J Since work done can also be treated as potential energy U = 1/2kx^2 3.212 = 1/2(500)x^2 x = 0.113 m and is still wrong, why??? Thanks!