Physics Math

Question

In an exciting game, a baseball player manages to safely slide into second base. The mass of the baseball player is 88.9 kg and the coefficient of kinetic friction between the ground and the player is 0.49.

A.) Find the magnitude of the frictional force in newtons.

 

B.) It takes the player 1.6 s to come to rest. What was his initial velocity (in m/s)?

Answer 1

(A)

 

f = μmg = 0.49(88.9)(9.8) N ≅ 426.9 N

 

(B)

 

-f = ma = m(0 - v_i)/t = -mv_i/t ⇒

 

v_i = tf/m = (1.6)(426.9)/(88.9) m/s ≅ 7.68 m/s