Physics

Problem

A cart on a frictionless track is attached to a horizontal spring. The spring constant is

2.5\,\text{N}\!\cdot\!\text{cm}^{-1}

. The cart is pulled

20\,\text{cm}

in the

-x

direction (to the left) and released but held momentarily at rest. What is the

x

-component of the spring force acting on the cart while it is held? a)

+0.50\,\text{N}

+5.0\,\text{N}

+50\,\text{N}

-50\,\text{N}