Magnitude of change in linear momentum

AI Thread Summary
The problem involves calculating the change in linear momentum of a 0.70 kg ball that strikes a wall while moving at 9.6 m/s and rebounds at 1.3 m/s. The formula used is Dp = mv(f) - mv(i), where the initial and final velocities are in opposite directions. The initial momentum was calculated incorrectly, leading to a result of -5.81, which was identified as wrong. The correct approach recognizes that the magnitude of the change in momentum should be positive, resulting in a final answer of 7.63 kg·m/s. Understanding the direction of velocities is crucial for accurate momentum calculations.
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Homework Statement



A 0.70 kg ball is moving horizontally with speed of 9.6 m/s when it strikes a vertical wall. The ball rebounds with speed of 1.3 m/s. What is the magnitude of the change in linear momentum of the ball?


Homework Equations



Dp = mv(f) - mv(i)

The Attempt at a Solution



I solved for mv(f) and mv(i). Solved for Dp which I got -5.81 which is wrong.
 
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Hint: The initial and final velocities point in opposite directions.
 
-.91 - 6.72 = -7.63

Is the answer positive because magnitude is positive?
 
That is correct.
 

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