Newtons 3 rd Law Newtons 1 st Law

Newton’s 3 rd Law

Newton’s 1 st Law How anrdobject behaves when there is NO net force Newton’s 3 Law acting on it. How a force on an object affects other objects. Newton’s 2 nd Law How an object behaves when there is a net force acting on it.

Newton’s 3 rd Law When one object exerts a force on another object, the second object exerts a force of equal size on the first object in the opposite direction.

1. A book pushes on a table with a force of 12 N. The table pushes _______ on the book with a force of upward 12 N _______. 2. A hand pushes on a spring with a downward force. The spring _______ pushes on the hand _______ with an Upward 40 N force ____________.

3. A girl’s weight _________ Pulls downward Force with a _______ of 600 N. The Pull upward rings ___________ with a force 600 N ______ of _______.

4. The action force is the car tires pushing on the ground. The reaction force is the ground pushing on the car tires.

5. The action force is the rocket pushing on the gas. The reaction force is the gas pushing on the rocket.

6. The action force is the earth pulling down on the ball. The reaction force is the ball pulling up on the earth.

7. As you stand on a floor, the floor exerts an upward force on your feet. Why don’t you accelerate upward from this force? Your weight and the normal force of the floor pushing up on you are equal but in opposite directions. They cancel out to zero, so you don’t accelerate.

250 N 8. A girl hangs from the ends of the rope as shown in the figure. If gravity pulls her downward with a forceof 500 N, what is the reading on the force scale near her left hand? 250 N The sum of the upward forces (250 N + 250 N) must equal the sum of the download forces (500 N).

What is the opposite force from Newton’s 3 rd Law? The downward force of a hammer on a nail. The upward force of the nail on the hammer.

What is the opposite force from Newton’s 3 rd Law? The force of gravity pulling down on a book. The force of gravity pulling up on the earth.

What is the opposite force from Newton’s 3 rd Law? The force of helicopter blades pushing air down. The force of air pushing helicopter blades up.

What is the opposite force from Newton’s 3 rd Law? The force of air resistance on a thrown baseball. The force of the baseball pushing forwards on the air.

10. In each of the situations shown in the figures below, does the force scale read 0 N, 100 N, 200 N, or something else? Why? 100 N, The total force to the right of the spring scale 100 N, These two situations are identical as far as the spring scale is concerned.