Serena Williams is returning a serve from her sister Venus. Below is the graph of the force of her racquet on the tennis ball. Use the following graph to answer questions 3 and 4

Identify the type of synthetic material used in each object

What is the coefficient of kinetic friction μk between the block and the tabletop?

You throw a small rock straight up from the edge of a highway bridge that crosses a river. the rock passes you on its way down, 7.00 s after it was thrown. what is the speed of the rock just before it reaches the water 28.0 m below the point where the rock left your hand? ignore air resistance.