1. You push a heavy car by hand. The car, in turn, pushes back with an opposite but equal force on you. Doesn’t this mean the forces cancel one another, making acceleration impossible? Why or why not?
-No, because of the system that is involved. The system would be you and the heavy car, therefore the action and reaction forces are internal and cancel out.
2. If you stand next to a wall on a frictionless skateboard and push the wall with a force of 30N, how hard does the wall push on you? If your mass is 60 kg, what is your acceleration?
30 N
-This I am not too sure how to do it. would you have to multiply 60kg and 30N?
3. When a rocket engine is above the Earth’s atmosphere, what does it push on to cause acceleration?
-The rocket recoils causing it to accelerate dude to the reaction forces that are exerted by the material the rocket fires.
5. A truck has a trailer attached. As the truck drives off it exerts a force on the trailer that tends to pull the trailer along. But, according to Newton's 3rd Law, the trailer exerts an equal and opposite force on the truck which tends to stop the truck. How, then, can the truck and trailer accelerate and drive off?
-There is a system involved where there is an external force happening when the road pushes on the trailer that's when the truck and trailer accelerates and drives off.
2. The forces cancel, so the net force is zero, and the acceleration is zero (f=ma).
Yes on 3. Newtons third law. There is no pushing against anything.
5. actually, the road is opposing the motion (friction). The net force of the tire on the road is greater than frcition opposing motion, and the truck acceleraltes. The truck-trailer force pair is internal, and cancels.
2. To determine how hard the wall pushes on you, you need to consider Newton's Third Law of Motion, which states that every action has an equal and opposite reaction. In this case, when you push on the wall with a force of 30N, the wall pushes back on you with an equal but opposite force of 30N.
However, the force exerted by the wall does not directly affect your acceleration since the wall is stationary and cannot move. Your acceleration depends on the net force acting on you, which is the difference between the force you exert on the wall and your own weight. To calculate your acceleration, you would need to use Newton's Second Law of Motion: force equals mass multiplied by acceleration (F = ma).
In this scenario, your acceleration would depend on the total force acting on you, which is 30N (the force you are exerting on the wall) minus your weight (which is mass multiplied by the acceleration due to gravity, assuming no other forces like friction are acting on you). Without the value of the acceleration due to gravity provided, it is not possible to determine your acceleration in this situation.
2. To find out how hard the wall pushes on you, you need to know your acceleration. Since you are standing still on a frictionless skateboard, your acceleration is zero. According to Newton's second law (F = ma), the force exerted by the wall on you is equal to your mass multiplied by your acceleration. So, if your mass is 60 kg and your acceleration is 0, the wall will exert a force of 0 N on you.
4. When a rocket engine is above the Earth's atmosphere, it pushes on the expelled gases. According to Newton's third law, for every action, there is an equal and opposite reaction. When the rocket engine expels gases with a high velocity, it creates a thrust force in the opposite direction, causing the rocket to accelerate forward.
5. In the case of a truck with a trailer attached, the force exerted by the truck on the trailer and the force exerted by the trailer on the truck are indeed equal and opposite. However, these forces act on different objects within the system. The force from the truck on the trailer causes the trailer to accelerate forward, while the equal and opposite force from the trailer on the truck tends to slow down the truck. Despite the equal and opposite forces, the overall movement and acceleration of the truck and trailer system are determined by other external forces, such as the friction between the tires and the road pushing on the trailer.