Physical Science - Chapter 4
Terms in this set (23)
the action and reaction pair of forces that occur in an interaction
mutual action between objects where each object exerts an equal and opposite force on the other
whenever the object exerts a force on a second object, the second object exerts an equal and opposite force on the first. Or put another way, "To every action there is always an opposed equal reaction."
Newton's Third Law
In the simplest sense, a force is a push or pull. In a deeper sense, what is a force?
It is a part of a mutual action- an interaction.
How many forces are required for an interaction?
It is required in pairs.
When you push against a wall with your fingers, they bend because they experience a force. Identify this force.
It is the same amount of force that you exerted onto the wall.
Why do we say a speeding object doesn't have force?
It possess it's own interia.
Whenever one object exerts a force on a second object, the second object exerts an equal and opposite force on the first.
Newtons Third Law of Motion.
Consider hitting a baseball with a bat. If we call the force on the bat against the ball the action force, identify the reaction force.
The reaction force is the ball moving after being hit by the bat.
If a bat hits a ball with 1000 N of force, how much does the ball hit back on the bat?
The ball would hit back with a force of 1,000 newtons.
If the world pulls you downward, what is the reaction force?
The ground pushing you upward.
If the forces that act on a cannonball and the recoiling cannon from which it is fired are equal in magnitude, why do the cannonball and cannon have very different accelerations?
A given force exerted on a small mass produces a large acceleration, while the same force exerted on a large mass produces a small acceleration.
Identify the force that propels a rocket.
The reaction force of the material it fires.
How can the net force on the ball be zero when you kick it?
The net force will zero if two opposing forces act on it.
Why does a push on the dashboard of a stalled car not accelerate the car?
There are two forces acting on it, the push and the brakes.
How many forces are exerted on the cart? What is the horizontal net force on the cart?
There are 2 forces exerted. The horizontal net force is the horse pulling on the cart and the cart pulling on the horse.
How many forces are exerted on the horse? What is the net force of the horse?
There are 4 forces exerted on the horse. There will be a net force if the horse pushes the ground with a greater force than its pull on the cart.
How many forces are exerted on the horse-cart system? What is the net force on the horse-cart system?
There are 6 forces exerted.
Which is most important in winning in a tug-of-war; pulling harder on the rope, or pushing harder on the floor?
Pushing harder on the floor.
How does a helicopter get its lifting force?
The blades force air particles down and the air forces the blades up.
A boxer can hit a heavy bag with great force. Why can't he hit a sheet of newspaper in midair with the same amount of force?
The paper isn't capable of exerting a reaction force.
Can you physically touch another person without that person touching you with the same magnitude of force?
Fill in the blanks. Newton's first law is often called the law of ; Newton's second law highlights the concept of ; and Newton's third law is the law of and .
inertia; acceleration; action and reaction