A tennis player pushes the tennis ball with her racquet over a distance of 0.5m. The ball gains (kinetic) energy of 50J. What was the average force during the "serve"?

M1 = 2.8 kg, m2 = 6.72 kg, m3 = 11.2 kg, byas in .is ,is .toof m3 it 0.91 m. (in m/s)

You want to move a heavy box with mass 30.0 kg across a carpeted floor. you pull hard on one of the edges of the box at an angle 30∘ above the horizontal with a force of magnitude 240 n, causing the box to move horizontally. the force of friction between the moving box and the floor has magnitude 41.5 n . what is the box's acceleration just after it begins to move

Which of the following should not be included in a great summary? a. blaming your lab partner b. new questions your experiment has generated c. your prediction d. your investigation plan