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?

Determine the time it takes for a satellite to orbit the earth in a circular "near-earth" orbit. the definition of "near-earth" orbit is one which is at a height above the surface of the earth which is small compared to the radius of the earth, so that you may take the acceleration due to gravity as essentially the same as that on the surface. does your result depend on the mass of the satellite?