Chapter 9, Problem 83A

To determine

To explain: The reason why the given method is effective.

Explanation of Solution

Introduction:

Impulse on an object is equal to the product of the force $F$ exerted on the object in a small time interval $\Delta t$ ,

  $J=F\Delta t$  ......(1)

Impulse can also be defined as the change in momentum of the object $\Delta p$ that is,$J=\Delta p$  ...... (2)

When the tether which connects the astronaut and the spaceship breaks, the astronaut uses a gas pistol in order to get back to the space ship.

The astronaut fires the gas pistol with some force in a small interval of time in the opposite direction to that of the spaceship. So according to Newton’s third law of motion, the pistol also exerted the same magnitude of the force in the opposite direction in the same time interval of time that is the pistol provides the necessary impulse for the astronaut to move towards the spaceship.

When the astronaut fires the gun, the impulse on the gun in the forward direction changes its momentum and the astronaut will move backward with the same change in momentum in the backward direction and get back to his ship.