http://www.ck12.org Chapter 7. Momentum Conservation
ii. One of the lab groups declares that the data on the floor alone demonstrate to a 2% accuracy that the
collision was elastic. Show their reasoning.
iii. Another lab group says they can’t make that determination without knowing the velocity the balls
have on impact. They ask for a timer. The instructor says you don’t need one; use your meter stick.
Explain.
iv. Design an experiment to prove momentum conservation with balls of different masses, giving
apparatus, procedure and design. Give some sample numbers.Answers to Selected Problems
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8. 37.5 m/s
9.v 1 = 2 v 2
- 24kg− 5 m
- 0.364 m/s
- 22kg− 5 m
- 109 N
- 109 N due to Newton’s third law
- 2.0 kg,125 m/s
- 21 m/s to the left
- 3250 N
- 90 sec
- 7 × 105 sec
- 60 m/s
2..700 sec - yes, 8.16 m
- 0.13 m/s to the left
- 11000 N to the left
- tree experienced same average force of 11000 N but to the right
- 2500 lb.
- about 2.5 “g”s of acceleration
- no change
- the last two cars
- 0.00912 s
- 0.0058 m/s^2
- 3.5 m/s^2
- 15 m/s
- 49◦S of E