Solve the all parts of given question:

Question: In an exciting game, a baseball player manages to safely slide into second base. The mass of the baseball player is 86.5 kg and the coefficient of kinetic friction between the ground and the player is 0.53.

Part A: Find the magnitude of the frictional force.

In N

Part B: It takes the player 1.5 s to come to rest. What was his initial velocity?

In m/s

Please answer with details of how you got to that answer. Thanks.