Question

A 0.140 kg baseball is thrown horizontally with a velocity of 28.9 m/s. It is struck with a constant horizontal force that lasts for 1.85 ms, which results in a velocity of 37.0 m/s in the opposite direction. What was the magnitude of the horizontal force?
A) 0.613 kN
B) 2.19 kN
C) 2.80 kN
D) 4.99 kN

Answer 1

Option D is the correct answer.

Explanation:

Force = Mass x Acceleration

F = ma

m = 0.14 kg

We have equation of motion v = u + at

     Initial velocity, u = 28.9 m/s

     Final velocity, v = -37 m/s    

     Time, t = 1.85 ms = 0.00185 s

     Substituting

                      v = u + at  

                      -37 = 28.9 + a x  0.00185

                      a = -35621.62 m/s²

    Acceleration, a = -35621.62 m/s²

F = ma = 0.14 x -35621.62 = -4.99 kN

Option D is the correct answer.