A 4.10 kg block is pushed along the ceiling with an constant applied force of F = 81.5 N that acts at an angle è = 52° with the horizontal, as in the figure below. The block accelerates to the right at 5.10 m/s2. Determine the coefficient of kinetic friction between the block and the ceiling.

Answer 1

A football punter accelerates a 0.61 kg foot- ball from rest to a speed of 9 m/s in 0.24 s.
What constant force does the punter exert on the ball?
Answer in units of N.