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whatisphys
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Homework Statement
Two spheres having masses M (sphere 1) and 2M (sphere 2) and radii R and 2R, respectively, are released from rest when the distance between their centers is 8R.
How fast will sphere 1 be moving when they collide? Assume that the two spheres interact only with each other. Enter your answer in units of sqrt(GM/R).
How fast will sphere 2 be moving when they collide? Enter your answer in units of sqrt(GM/R)
Homework Equations
-Gmm/r
(mv^2)/2
m1v1 + m2v2 = 0 since starts at rest
The Attempt at a Solution
Okay.
So what I did was I first calculated initial PE and Final PE. I then calculated the change in PE which turned out to be -5GM^2/12R
Then, I equated it to deltaKE = -deltaPE which i got as (Mv1^2)/2 + (2Mv2^2)/2 = 5GM/12R.
I used conservation of momentum to find out the ratio of V1 to V2 which was V2 = -1/2(V1)
After that I substituted that to the equation above and solved for V1 as 20GM/36R.
But it says it is wrong. Any help would be appreciated. Thank you