A rocket obeys the principles of recoil. However, it is much more difficult to apply Newton's second law to a rocket because
A) Newton's three laws do not apply in outer space.
B) there is actually sideways momentum, because a rocket motor is just a well-controlled explosion.
C) the rocket pushes against air but the air is a fluid.
D) as the rocket motor fires the total mass of the rocket changes.

Question

Quizplus · Accepted Answer

Newton's second law states that force is equal to mass times acceleration. However, in the case of a rocket, the mass is constantly changing as fuel is burned up and expelled out of the rocket, making it difficult to calculate the exact acceleration and therefore the force being applied.

A Rocket Obeys the Principles of Recoil