Okay, I did this problem, and my answer disagrees with the book.(adsbygoogle = window.adsbygoogle || []).push({});

A 15.0 g rubber bullet hits a wall with a speed of 150 m/s. It bounces straight back with a speed of 120 m/s. what is the change in momentum?

I get:

delta p=(m*v-i) - (m*v-f)

delta p= (15.0g * 150 m/s) - (15.0 g - 120 m/s) = 15.0 g(150m/s - 120 m/s) = 15.0g * 30 m/s

delta p = 450g * m/s = .45 kg * m/s

the book says the answer is 4.05 kg * m/s

Am I wrong?

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# Homework Help: What is the change in momentum?

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