Question

prove that a body can move without force

Answer 1

if u are standing on a steep hill and have to push your car because u dont have petrol in it to run it it would be easier to do it. 
but if u do same thing on a flat road it would be difficult.

Answer 2

In an atmosphere without friction ie in ideal condition 
If a force is exerted in a direction say $\alpha$ so the body will move in the direction -$\alpha$ .So in this condition after unit time say 1 sec the body will move because there is no force opposing it nd not by that existing force .
Hence proved a body can move without force