Question

A rocket ship at rest in space gives a short blast of its engine, firing 50 kg of exhaust gas out the back end with an average velocity of 400 m/s. What is the change in momentum of the rocket during this blast?

Answer 1

The change in momentum of the rocket (also known as impulse) during the blast is 20,000 kg·m/s. This is calculated by multiplying the mass of the exhaust gas (50 kg) by its average velocity (400 m/s).

Step-by-step explanation:

The change in momentum of the rocket during the blast (also known as impulse) can be calculated using the conservation of momentum. The momentum of the exhaust gas expelled will be equal in magnitude and opposite in direction to the change in momentum of the rocket.

To calculate the change in momentum of the rocket, we use the formula:

Change in momentum = mass of exhaust × velocity of exhaust.

In this case, the mass of the exhaust gas is 50 kg, and the average velocity at which it is expelled is 400 m/s:

Change in momentum = 50 kg × 400 m/s = 20000 kg·m/s.

This is the momentum gained by the rocket in the opposite direction, due to Newton's third law of motion.

Answer 2

20,000 Ns

Step-by-step explanation:

mass of exhaust gases, m = 50 kg

velocity of exhaust gases, v = 400 m/s

The momentum of a body is defined as the measurement of motion of body. mathematically, it is defined as the product of mass off the body an its velocity.

change in momentum of rocket = final momentum - initial momentum

= m x v - 0

= 50 x 400

= 20,000 Ns