# Homework Help: Spring, Block, KE, PE, Incline Problem: Why is KE=ZERO?

1. Nov 5, 2012

Spring, Block, KE, PE, Incline Problem: Why is KE=ZERO??

A 250 g block is pressed against a spring of force constant 1500 N/m until the block compresses the spring 8.0 cm. The spring rests at the bottom of a ramp inclined at 60.0 degrees to the horizontal. Using energy considerations, determine how far up the incline the block moves from its initial position before it stops if:

a) the ramp exerts no friction force on the block

b) if the coefficient of kinetic friction is 0.400

Can someone explain to me why is the change in kinetic energy = to zero??

The solutions says KE is zero because initial and final states are stationary. What does that mean? Doesn't the box move...

Maybe I don't fully understand the concepts...

a) 2.26 m
b) 1.84 m

2. Nov 5, 2012

### mishek

Re: Spring, Block, KE, PE, Incline Problem: Why is KE=ZERO??

When you start, your velocity is zero, when you stop it's zero again.

3. Nov 5, 2012