## Question

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. ^{ }

### Solution

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**.

#### SIMILAR QUESTIONS

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(*R _{e}* = 6400 km,

*g*= 10 ms

^{–2})

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.

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