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Taking the potential energy to be zero at infinite separation, find the potential energy of a 118.0-kg object at the surface of the earth. (Use 6.37E+6 m for the earth's radius.)

I did this and got -7.374E09.

It then asks Find the escape speed for a body projected from this height.

I do not understand the concept of escape speed. In my book it gives this equation: sqrt 2gRe

It then goes on to solve the equation to be 11.2km/s.

How do I use this equation or the concept of escape speed to solve this problem.

Thanks for the help.

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# Homework Help: Escape Speed is weird

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