Question

PLEASE HELP ASAP

A 2.9 kg model rocket accelerates at 15.3 m/s2 with a force of 44 N. Before launch, the model rocket was not moving. After the solid rocket engine ignited, hot gases were pushed out from the rocket engine nozzle and propelled the rocket toward the sky. Which of Newton’s laws apply in this example? Check all that apply.

A the first law

B the second law

C the third law

D the fourth law

E the fifth law

Answer 1

Hello!

As per my understanding, the answer is A, B, and C - the first law, the second law and the third law respectively.

Look at the definitions of the three laws and your problem above and you will be able to figure it out.

Good luck :)

Answer 2

A the first law

B the second law

C the third law

Step-by-step explanation:

All three Newton laws are involved in this example. Let's see why:

1) First Law: "an object which has a zero net force acting on it stays at rest if it was at rest or continue to move at constant speed if it was already moving" --> this law applies to the first part of the problem, before the launch, when the rocket is not moving: since no forces are acting on it, it stays at rest.

2) Second law: "a net force F applied to an object of mass produces an acceleration a given by the relationship:

`F=ma`"

This law applies when the rockets starts its motion: in fact, a force of 44 N is applied to the rocket of mass 2.9 kg, and its acceleration is a=15.3 m/s^2, and we see that these numbers satisfy the previous equation.

3) Third law: "when an object A exerts a force on object B, object B exerts an equal and opposite force on object A"

This law applies when the rocket is in motion: in fact, the rocket pushes the hot gases outside, so the hot gases pushes back on the rocket, accelerating it so it moves forward.