1. The problem statement, all variables and given/known data A 1.2 kg spring laboratory cart is held against a wall. The spring constant is 65.0 N/m. The spring is compressed 8.0 cm when held against the wall. What is the compression of the spring when the cart's velocity is 42.0 cm/s? 2. Relevant equations (1/2)mv^2=(1/2)kx^2 3. The attempt at a solution (1.2)(0.42)^2=65(x)^2 x=5.71 cm But the answer says 5.6 cm, so I think I did something wrong.