A charging elephant with mass 5230kg comes toward you with speed of 4.45m/s. You toss a 0.15 rubber ball at the elephant with a speed of 7.91 m/s. (a) When the ball bounces back toward you, what is the speed?(adsbygoogle = window.adsbygoogle || []).push({});

Answer= 16.8

I don't know if the answer is written wrong in the back of the book or if I'm oversimplifying it.

Since the mass of the elephant is so big compared to the ball shouldn't it just be 2 x 7.91?.

I just used v2,f = (2m1/(m1+m2))v0

since m2 approaches zero I would expect (2m1/m1)v0 --> 2v0

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# Homework Help: Elastic Collision of a ball and an elephant

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