A ball travelling at hits a wall and rebounds at in the opposite direction. What is the magnitude of the change in momentum?
Answer and explanation
Correct answer: B.
- Step 1: Take the initial direction as positive: final velocity m/s.
- Step 2: Change in momentum kg m/s.
- Step 3: The magnitude is kg m/s.
Answer
.
Why not the others: : subtracts the speeds, ignoring the change of direction. : uses the initial momentum only. : uses the final momentum only.
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