Change in momentum after hitting a wall

Thread starter gake
Start date Jun 10, 2013
Tags

Change Change in momentum Momentum Wall

AI Thread Summary

The discussion revolves around calculating the change in momentum when a 1.0 kg ball traveling at 4.0 m/s strikes a wall and bounces back at 2.0 m/s. The correct answer for the change in momentum is determined to be 6 kg m/s, corresponding to option C. The user initially miscalculated the change in momentum as 2 kg m/s, not accounting for the direction of the velocities. The importance of considering the sign associated with velocity in momentum calculations is emphasized. This highlights a common error in physics problems involving momentum and direction.

Jun 10, 2013

gake

Homework Statement

32) The change in momentum, in kg m/s, that occurs when a 1.0 kg ball traveling at 4.0 m/s strikes a wall
and bounces back at 2.0 m/s is
A) 2.
B) 4.
C) 6.
D) 8.
Answer: C

Homework Equations

Momentum==Mass*Velocity

The Attempt at a Solution

I get A.

Momentum₁==1*4
Momentum₂==1*2

Momentum₁-Momentum₂==2

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Jun 10, 2013

lewando

Homework Helper

Gold Member

Consider the "sign" associated with the two velocities.

Jun 10, 2013

gake

What a dumb mistake! Thanks :)

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