Problems
8.1 Linear Momentum, Force, and Impulse

A 145-g baseball is incoming at a velocity of 35 m/s. The batter hits the ball as shown in the image. The outgoing baseball has a velocity of 40 m/s at the angle shown.
What is the magnitude of the x-component of the impulse?
-
0.26 kgâ‹…m/s.
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4.09 kgâ‹…m/s.
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4.35 kgâ‹…m/s.
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8.44 kgâ‹…m/s.
For how long should a force of 130 N be applied to an object of mass 50 kg to change its speed from 20 m/s to 60 m/s?
- 0.031 s
- 0.065 s
- 15.4 s
- 40 s
8.3 Elastic and Inelastic Collisions
In an elastic collision, an object with momentum 25 kg⋅m/s (moving to the left) collides with another that has a momentum 35 kg⋅m/s, moving toward it to the right. The first object’s momentum changes to 15 kg⋅m/s, and it is now moving to the right. What is the magnitude of the momentum of the second object after the collision?
- 5 kgâ‹…m/s
- 10 kgâ‹…m/s
- 25 kgâ‹…m/s
- 75 kgâ‹…m/s
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-0.12\,\text{m/s}
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0\,\text{m/s}
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0.12\,\text{m/s}
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7.5\,\text{m/s}