P5 - Action and reaction

Question 1

What are the units for momentum?

Answer 1

kgm/s

Question 2

What is conservation of momentum?

Answer 2

The idea that the momentum before a collision is equal to the momentum afterwards.

Question 3

How do rockets move?

Answer 3

• inside a rocket some of the fast moving gas particles colliding with the walls create a force
• in addition, some particles are forced down out of the case of the rocket at high speed
• this results in an equal and opposite reaction force, launching the rocket