Read the following selection from the section "Energy Can Change Form."
The ball's kinetic energy is changed
into heat by the opposing force of
friction. Friction is the force resisting
objects sliding against each other.
The ball stops at the bottom of the
hill because friction transforms all its
kinetic energy into heat. As with
energy transfers, the amount of
energy stays the same in
transformations.
Based on this selection, choose the statement
that is TRUE.

You are driving to the grocery store at 20 m/s. you are 110m from an intersection when the traffic light turns red. assume that your reaction time is 0.50s and that your car brakes with constant acceleration. how far are you from the intersection when you begin to apply the brakes? what acceleration will bring you to rest right at the intersection? how long does it take you to stop after the light changes? the known values: vi=20m/s xi=110m t=.50s vf=0m/s xf=0m a=?