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

[ladyrx2020]

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...

Answers:
a) 2.26 m
b) 1.84 m

 

[mishek]

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

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

 

[ladyrx2020]

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

Ohhh! I see! Wow that was a quick reply to my first post ever. Hahaha thanks a bunch! x3 :!)