Question

3.1.2 quiz: newtons laws of motion
question 6 of 10
how does newtons third law explain how a rocket is launched upward?

a. the force of earths gravity balances with the force of the rocket engines.

b. the rocket will remain motionless on the launchpad until an unbalanced force is applied.

c. the mass of the rocket determines how much force is needed to move it into orbit.

d. the force it exerts on its exhaust gases is equal to the force the exhaust gases exert on the rocket.

Explanation:

Newton's third law states that for every action, there is an equal and opposite reaction. When a rocket launches, it expels exhaust gases (action force), and the exhaust gases exert an equal and opposite force on the rocket (reaction force), propelling it upward.

• Option A refers to balanced forces (related to Newton's first law for equilibrium), not third law.
• Option B describes Newton's first law (inertia), not third law.
• Option C relates to Newton's second law (force, mass, acceleration), not third law.
• Option D correctly describes the action - reaction pair as per Newton's third law.

Answer:

D. The force it exerts on its exhaust gases is equal to the force the exhaust gases exert on the rocket.