An astronaut (in space) leaves his spaceship, with an acceleration of 100m/s^2, no gravitational force from any planet, negligible force from space ship, why does acceleration turn to zero as soon as he leaves his space ship, according to law of inertia, an external force must be required to stop a body. Why?

Question

anonymous · Answer

lol....Since there is no accelration....F = 0.......Becoz..... F = M * A  if a =0 F---> 0

anonymous · Answer

no gravitational force from any planet , .....and No air....to resist

anonymous · Answer

we need an external force,to stop it F=0,but Velocity isn't zero

shane_b · Answer

While is he is in the ship he is accelerating with the ship at a rate of 100m/s^2.  Once he leaves the ship he is no longer accelerating because the force that is causing the acceleration of the ship (ie rockets) is no longer acting on him.  

Therefore, he will continue moving in the same direction at the same velocity he was at when he left the ship until some force begins acting on him again.  You should remind yourself of Newton's 1st Law to understand why.

anonymous · Answer

Thanks, I get it