A body is projected from the earth’s surface with the intention of letting it escape from the earth’s gravitational field. What is the minimum escape velocity of the body? [Earth’s radius = 6.4 x 103km, g = 10ms-2]
- 14 kms-1
- 13 kms-1
- 12 kms-1
-
11 kms-1
The correct answer is: D
Explanation
Velocity = \(\sqrt2gR\)= 2 x 6400 x 100 x 10
= 11 km-1