I'm taking a module in physics, and I'm quite confused with applying Newton's third law of motion. I know in the following examples we are usually just interested in the forces acting on the book and the car, but to understand it I wanted to take a look at the big picture, so could you let me know if I have the basic idea.
Say you have a book resting on a table which is resting on the floor. You end up with four pairs of forces.
Force due to gravity on the book, equal and opposite one on the earth.
A contact force on the table equal to the force due to gravity on the book, and a normal reaction force on the book equal and opposite to the contact force.
... then you have two more pairs: one between the desk and the earth and one between the floor and the desk. The force of the floor on the desk is equal and opposite to the contact force of the book on the table and the weight of the table.
so thats 1 problem. I'm not sure if I have the right idea, but hopefully one of you can help me out. And with the car:
1: tire pushes back on road, road pushes forward on car 2.friction pushes back on the car and forward on the road, easily overcome.
and I guess air resistance and other forces eventually bring the car to a contstant velocity.