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Question:

A satellite is moving with a constant speed 'V' in a circular orbit about the earth. An object of mass 'm' is ejected from the satellite such that it just escapes from the gravitational pull of the earth. At the time of its ejection, the kinetic energy of the object is?

3/2mV2

2mV2

1/2mV2

mV2

Solution:

V is the orbital velocity and Ve is the escape velocity then Ve = √2V
The kinetic energy at the time of ejection KE = 1/2mVe2 = 1/2m(√2V)2 = mV2