A 6 kg trolley moving at 11 m/s hits a stationary 2 kg trolley and they stick together. What is their speed afterwards?
Answer and explanation
Correct answer: D. 8.25 m/s
- Step 1: Momentum is conserved: 6 x 11 = (6+2) v.
- Step 2: v = 66/8 = 8.25 m/s.
Answer
8.25 m/s.
Why not the others: 11 m/s, 33 m/s and 5.5 m/s do not fit.
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