Problem 1: The velocity of a particle moving along the x-axis varies
according to the expression vx = (40 – 5t 2) m/s, where
t is in seconds.
Find the average acceleration in the time interval
t=0 to t= 2.0 s.

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?