Two skaters initially at rest push against each other so that they move in opposite directions. What is the total momentum of the two skaters when they begin moving

The frequency of the fundamental of the guitar string is 320 hz. at what speed v do waves move along that string?

Which of the following statements correctly describes a transformer?

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=?