Q39 of 81 Page 225

A mass of 6 × 1024 Kg (equal to the mass of the earth) is to be compressed in a sphere in such a way that the escape velocity from its surface is 3 × 108 ms-1. What should be the radius of the sphere?

To find the escape velocity, the gravitational pull by a body or its potential energy at the surface should be equal to its kinetic energy.






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