A 2 kg ball hits a wall at 2 mĀ·sā»Ā¹ and rebounds in the opposite direction at 6 mĀ·sā»Ā¹. Calculate the magnitude of the change in momentum of the ball.
Answer and explanation
Correct answer: D.
- Step 1: Choose the direction of the rebound as positive: mĀ·sā»Ā¹ and mĀ·sā»Ā¹.
- Step 2: kgĀ·mĀ·sā»Ā¹.
Answer
.
Why not the others: : the velocities were subtracted, ignoring the reversal of direction. : only the initial momentum was used. : only the final momentum was used.
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