Question
Question: The escape velocity of a body on the surface of the earth is 11.2 km/s. If the earth's mass increase...
The escape velocity of a body on the surface of the earth is 11.2 km/s. If the earth's mass increases to twice its present value and radius of the earth becomes half, the escape velocity becomes –
A
5.6 km/s
B
11.2 km/s
C
22.4 km/s
D
44.8 km/s
Answer
22.4 km/s
Explanation
Solution
Ve = 
= 11.2 km/s
Now M' = 2Me & R' = Re/2
so 
= 
= 2
= 2 × 11.2
= 22.4 km/s