Gravitation Question 1
Question 1 - 24 January - Shift 1
The weight of a body at the surface of earth is 18 $N$. The weight of the body at an altitude of 3200 $km$ above the earth’s surface is (given, radius of earth $R_e=6400 km$ )
(1) $9.8 N$
(2) $4.9 N$
(3) $19.6 N$
(4) $8 N$
Show Answer
Answer: (4)
Solution:
Formula: Effect of Altitude
Acceleration due to gravity at height $h$
$g^{\prime}=\frac{g}{[1+\frac{h}{R}]^{2}}$
So weight at given height
$mg^{\prime}=\frac{mg}{[1+\frac{h}{R}]^{2}}=\frac{18}{[1+\frac{1}{2}]^{2}}=8 N$
