Question

Explain how the conservation of momentum is responsible for the propulsion of a rocket.

Answer 1

Rocket propulsion is an example of conservation of momentum

As momentum is given in one direction to exhaust gases, it is given in the other direction to the rocket.

Consider a rocket of finite mass m1 and amount of fuel m2.

in the beginning, the rocket is stationary and no exhaust gases are expelled.

p(net ) = 0

after the mass is ejected

p(net) = p(rocket) + p(fuel)

p(net) = m1v1 + m2v2

since v1 and v2 are in opposite direction, the rocket gets a net momentum which is equal to the momentum of fuel ejected