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

A certain spherical planet which is not rotating has a radius of 6.36 x 10^{5}m and a mass of 1.89 x 10^{21}kg. At what minimum speed would a vehicle traveling along its surface just begin to leave the ground?

2. Relevant equations

F_{C}= mv^{2}/r

F_{G}= GMm/d

3. The attempt at a solution

My problem is I don't know how to set the initial equation up: Is it,

F_{C}= GMm/d^{2}= mv^{2}/d

Or is it,

1/2mv^{2}= GMm/d?

They will differ by a factor of root 2.

If it was vertical velocity I would know it needs to be KE = PE, but since it's horizontal I'm confused. Can someone explain?

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# Homework Help: Centripetal force or escape velocity?

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