(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

A ball of mass M travelling at non-relativistic speed v elastically collides with a stationary ball of mass m.

(a)Show that the maximum speed which the second ball can have is:

2Mv/(M+m)

(b)What is the minimum speed?

3. The attempt at a solution

(a)

Method 1

Go into ZMF frame:

step 1: find V_{CM}

step 2: u_{2}' = u_{2}- V_{CM}

step 2: p_{i}= p_{f}= 0

step 3: v_{2}' = -u_{2}

step 4: go back into lab frame by adding V_{CM}

Method 2

1)Speed of approach = speed of separation

2)conservation of momentum

3)done.

But the puzzling thing is that why is this themaximumspeed? Isn't this the actual acquired speed?

(b)

Do we assume a head-on collision? If it is a head-on collision won't the speed be the same as part (a)?

assuming a non head-on collision by including angles and stuff doesn't help..

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# Homework Help: 2-body collision: Min and Max speed

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