devarshi-dt-logo

Question:

A satellite is revolving in a circular orbit at a height h from the earth surface, such that h << R where R is the radius of the earth. Assuming that the effect of earth's atmosphere can be neglected the minimum increase in the speed required so that the satellite could escape from the gravitational field of earth is :

√2R

√2gR

√gR(√2š•’µ)

√gR2

Solution:

The correct option is A√gR(√2š•’µ)
As we know that escape velocity is given by;
v0=√g(R+h)ā‰ˆāˆšgR
ve=√2g(R+h)ā‰ˆāˆš2gR
Ī”v=veāˆ’v0=(√2š•’µ)√gR