Question

as a rocket burns fuel, it becomes lighter and accelerates faster. this demonstrates: newton’s second law newton’s third law newton’s first law the law of conservation of energy multiple choice 1 point in a system such as bumper cars or rockets, what do newton’s laws eliminate all external forces. only describe the motion of one object. measure only the strength of gravity.

Explanation:

Newton's Second Law is $F = ma$ (force equals mass times acceleration). As a rocket burns fuel, its mass decreases. With a constant - thrust force (assuming the engine's thrust remains the same), according to $a=\frac{F}{m}$, as $m$ decreases, $a$ (acceleration) increases. Newton's First Law is about an object's tendency to stay at rest or in uniform - motion unless acted upon by an external force. Newton's Third Law is about action - reaction pairs. The Law of Conservation of Energy is about the total energy of a closed system remaining constant. For the second question, Newton's Laws are used to describe the motion of objects and the forces acting on them in a system like bumper cars or rockets, not to eliminate external forces, nor to measure only the strength of gravity, and they can describe the motion of multiple objects in a system.

Answer:

First question: Newton's Second Law
Second question: None of the provided options are correct. Newton's Laws describe the motion of objects and the forces acting on them in a system.