Question

A catcher catches a 145 g baseball that was originally traveling horizontally at 36.0 m/s towards the North. (a) Calculate the change in momentum of the baseball when it is caught. (b) What is the impulse that the catcher’s glove imparts on the baseball? (c) What is the impulse that the baseball imparts on the catcher’s glove? (d) If the ball takes 20 ms to stop once it is in contact with the catcher’s glove, what average force did the ball exert on the catcher?

Answer 1

Answer: a) Change in momentum (Δp) = 5.22 N.s

b) Impulse (I) = 5.22 N.s

c) Impulse = 5.22 N.s

d) Average Force = 261 N

Explanation: a) Change in momentum is the product of mass of the object and its change in velocity:

Δp = m(Δv)

Δp = m.(v - v₀)

Δp = 0.145(0 - 36)

Δp = - 5.22 N.s

When it is caught, the change in momentum is Δp = - 5.22 N.s

b) Change in moment is also Impulse, so: Δp = I = 5.22 N.s.

c) According to Newton's Third Law, "for every action, there is an equal and opposite reaction", the Impulse the baseball imparts on the glove is the same of that of the glove on the baseball, with opposite signs (which means opposite direction), so I = - 5.22 N.s.

d) Impulse is is the product of force applied on an object and the amount of time it is applied:

Δp = F.Δt

F = Δp / Δt

F =
`(5.22)/(0.02)`

F = 261

The ball exerted an average of F = 261 N on the glove of the catcher.