Question

what will be the escape velocity from the planet earth if its radius is made 4 time​

Answer 1

Answer

Correct option is

A

67.2 m/s

Ve=  

Re

2Gue

​

 

​

 

=  

2gRe

​

 

≃11km/s

V=  

2(9g)4Re

​

 

=6×11km/s

=66km/s

Hence, option (A) is correct.

Answer 2

Answer:

Explanation:

The escape velocity for a planet is v  

e

​

 a particle starts from rest at a large distance from the planet, reaches the planet only under gravitational attraction, and passes through a smooth tunnel through its centre. Its speed at the centre of the planet will be