JEE MAIN - Physics (2022 - 26th July Morning Shift - No. 14)

The percentage decrease in the weight of a rocket, when taken to a height of $$32 \mathrm{~km}$$ above the surface of earth will, be :

$$($$ Radius of earth $$=6400 \mathrm{~km})$$

1%
3%
4%
0.5%

Explanation

$$\because$$ $$g = {{GM} \over {{r^2}}}$$

$$ \Rightarrow {{\Delta g} \over g} = 2{{\Delta r} \over r}$$

$$ \Rightarrow {{\Delta g} \over g} \times 100 = 2 \times {{32} \over {6400}} \times 100\% = 1\% $$

$$\Rightarrow$$ % decrease in weight = 1%

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