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1- Force of a Baseball Swing. A baseball has mass 0.139 k g . A- If the velocity

ID: 2116983 • Letter: 1

Question

1-Force of a Baseball Swing. A baseball has mass 0.139

kg .

A-If the velocity of a pitched ball has a magnitude of 41.0

m/s and the batted ball's velocity is 53.0m/s in the opposite direction, find the magnitude of the change in momentum of the ball and of the impulse applied to it by the bat.

B-If the ball remains in contact with the bat for 2.3

ms , find the magnitude of the average force applied by the bat.


2-On a frictionless, horizontal air table, puck A (with mass 0.250

kg ) is moving toward puck B (with mass 0.355kg ), that is initially at rest. After the collision, puck A has a velocity of 0.122m/s to the left, and puck B has velocity 0.655m/s to the right.

A-What was the speed of puck A before the collision?

B-Calculate the change in the total kinetic energy of the system that occurs during the collision


Explanation / Answer

1- change in momentum = m(v2 - v1)

= 0.139*(53 - (-41))=13.066 Kgm/s


Impulse = 13.066 Ns


Impulse = F*t

=> F = 5.68 KN


2- Pinitial = P final

=> 0.25*V= 0.25*0.122 - 0.355*0.655

=> V = -0.8081

=> V = 0.8081 m/s due right


change in KE = 0.5[ 0.25*0.122^2 + 0.355*0.655^2 - 0.25*0.8081^2]

= -3.61 mJ


decrease in KE by 3.61 mJ