Q.

The escape velocity of a body on the earth surface is 11.2 km/s. If the same body is projected upward with velocity 22.4 km/s, the velocity of this body at infinite distance from the centre of the earth will be:               [2023]
 

1 11.22 km/s  
2 Zero  
3 11.2 km/s  
4 11.23 km/s  

Ans.

(4)

The velocity at infinite distance when speed of projection and escape velocity are given, v2=v2-ve2

where v is projection velocity 

ve is escape velocity. Given, v=2ve

So,  v=(2ve)2-ve2 ;

        v=3ve=11.23 km/s