posted by Liz .
fill in the blank ( Energy and momentum unit)
1. the work done to stretch a spring is not equal to the to force multiplied by displacement because force is ____ as the spring stretches
2. A child goes down a slide at the playground, gaining speed as she goes. Her momentum ____ because there is the presence of a(n) ____
the force increases as the spring stretches
F = k x
work = k x^2/2
an external force, mg