1. Newton\'s first law states that an object will move with a constant velocity
ID: 2116448 • Letter: 1
Question
1. Newton's first law states that an object will move with a constant velocity if nothing acts on it. This seems to contradict our everyday experience that all moving objects come to rest unless something acts on it to keep it going. Does our everyday experience contradict one of Newton's Laws? If it does not, explain the apparent contradiction. If it does, explain why we bother to teach Newton's first law anyway.
2. Newton's third law says that objects that touch each other exert forces on each other that satisfy:
If object A exerts a force on object B, then object B exerts a force back on object A and the two forces are equal and opposite
Consider the following three situations concerning two identical cars and a much heavier truck.
In which of these situations do you think Newton's 3rd law holds or does not hold? Explain your reasons for saying so.
3. Newton's second law written in equation form states
a= FNET/m
Your roommate says %u201CThat's silly. Everyone knows it takes a force to keep something going at a constant velocity, even when there's no acceleration.%u201D Do you agree with your roommate? If so, explain why physics classes bother to teach the law. If you disagree, how would you try to convince your roommate of the error of his/her ways?
1. Newton's first law states that an object will move with a constant velocity if nothing acts on it. This seems to contradict our everyday experience that all moving objects come to rest unless something acts on it to keep it going. Does our everyday experience contradict one of Newton's Laws? If it does not, explain the apparent contradiction. If it does, explain why we bother to teach Newton's first law anyway.
2. Newton's third law says that objects that touch each other exert forces on each other that satisfy:
If object A exerts a force on object B, then object B exerts a force back on object A and the two forces are equal and opposite
Consider the following three situations concerning two identical cars and a much heavier truck.
- One car is parked and the other car crashes into it.
- One car is parked and the truck crashes into it.
- The truck is pushing the car, because the car's engine cannot start. The two are touching and the truck is speeding up.
In which of these situations do you think Newton's 3rd law holds or does not hold? Explain your reasons for saying so.
3. Newton's second law written in equation form states
a= FNET/m
Your roommate says %u201CThat's silly. Everyone knows it takes a force to keep something going at a constant velocity, even when there's no acceleration.%u201D Do you agree with your roommate? If so, explain why physics classes bother to teach the law. If you disagree, how would you try to convince your roommate of the error of his/her ways?
Explanation / Answer
1. Its improtant to note that the objects will continue to move with constant velocity means it could constantly be at rest also. So zero velocity is the case in this example. So Newton's laws are not violated, the reasoning given is flawed. :) :) :)
2. In all the three situations the newtons third law is valid. The contact force on all near the surfaces in all the three situations will be the same. If that is not the case then that surface will start to deform since unbalanced forces will tend to accelerate the surfaces.
3. When there is no acceleration, the net force on the object is zero. So the object will continue to move with its constant velocity when acceleration is zero. The reason practically why everyone needs force is that, there are certain frictional forces which oppose ideal motion.
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.