Cheryl runs a race on a circular 400.0 m track. she starts running east of the starting line and stops 20.0m west of the starting line. Her time is 8.0 × 10^1s. What is her average speed?

A1-lb collar is attached to a spring and slides without friction along a circular rod in a vertical plane. the spring has an undeformed length of 5 in. and a constant k =25 lb/ft. knowing that the collar is released from being held at a determine, the speed of the collar and the normal force between the collar and the rod as the collar passes through b.