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

Two Jupiter-size planets are released from rest 1.30×10^11 m apart.

What are their speeds as they crash together?

2. Relevant equations

3. The attempt at a solution

I have done K_f + U_f = K_i + U_i with K_i being zero because they have crashed together so... K_f + U_f = U_i is the equation I get....when solving for velocity final I get v_f = sqrt(2*G*m*(-1/r_i +1/r_f)) and Im not so sure I am making r_i and r_f the right values, I have made r_i the 1.30×10^11 and the r_f to be 2*radius of Jupiter which is 6.99*10^7 (from book) I keep getting v_f to be 42,566 m/s but thats not right

also from book the mass of jupiter is 1.90*10^27 kg...

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# Homework Help: Another Gravitational potential energy problem

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