Question 188: Gravitation

Question

The value of acceleration due to gravity at
Earth's surface is 9.8 ms
–2
. The altitude above
its surface at which the acceleration due to
gravity decreases to 4.9 ms
–2
, is close to :
(Radius of earth = 6.4 × 10
6
m)

Accepted Answer

$${{GM} \over {{{\left( {R + h} ight)}^2}}} = {{GM} \over {2{R^2}}}$$
$$R + h = \sqrt 2 R$$
$$h = \left( {\sqrt 2  - 1} ight)R \simeq 2.6 	imes {10^6}m$$

Answer

1.6 × 10
6
m

Answer

9.0 × 10
6
m

Answer

6.4 × 10
6
m

Answer

2.6 × 10
6
m

Gravitation

The value of acceleration due to gravity at Earth's surface is 9.8 ms –2 . The altitude above its surface at which the acceleration due to gravity decreases to 4.9 ms –2 , is close to : (Radius of earth = 6.4 × 10 6 m)

Choose the correct answer: