A 6.0kg box moving at 3.0m/s on a horizontal, frictionless surface runs into a light spring of force constant 75 N/cm. Use the work-energy theorem to find the maximum compression in the spring.
W = K2 - K1
W = (1/2)*m*v^2 - (1/2)*m*vo^2
W = - (1/2)*k*x^2
The Attempt at a Solution
- (1/2)*k*x^2 = 0 - (1/2)*m*vo^2, where k = 75000N/m
x = ((m*v^2)/k)^(1/2) = ((6.0kg*(3m/s)^2)/75000N/m)^(1/2)
x = 0.027m
But the answer in the book is x = 0.085m. I just can't see what I am doing wrong unless my textbook is wrong.