At A Point Above The Surface Of The Earth, The Gravitational Potential Is  and The Acceleration Due To Gravity Is 6.4 Ms–2. Assuming The Mean Radius Of The Earth To Be 6400 Km, Calculate The Height Of This Point Above The Earth’s Surface.   

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At a point above the surface of the earth, the gravitational potential is  and the acceleration due to gravity is 6.4 ms–2. Assuming the mean radius of the earth to be 6400 km, calculate the height of this point above the earth’s surface.   


Correct option is

1600 km


Let r be the distance of that point from the centre of the earth. Then


Dividing eq. (i) by the eq. (ii), we get


∴ Height of the point from the earth’s surface = 8000 km – 6400 km =1600 km



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