A 6 kg trolley moving at 8 m/s hits a stationary 1 kg trolley and they stick together. What is their speed afterwards?
Answer and explanation
Correct answer: A. 6.857 m/s
- Step 1: Momentum is conserved: 6 x 8 = (6+1) v.
- Step 2: v = 48/7 = 6.857 m/s.
Answer
6.857 m/s.
Why not the others: 8 m/s, 48 m/s and 4 m/s do not fit.
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