Motion
Change in the position of an object and described in terms of its speed and direction
What is motion?
Push or pull that acts on an object
Force that results when two materials rub against each other or when their contact prevents sliding
What is Friction?
At the release point
The change in one object's position compared with another object's position
What is relative motion?
A force that required two pieces of matter to touch
What are contact forces
Equal forces that combine to act on an object from opposite directions cancel each other out
What are balanced forces?
An object in motion will stay in motion and an object at rest will stay at rest
What is Newton's First Law?
When you hit a baseball with a bat, the baseball moves away. Does the bat slow down?
Yes, equal and opposite force makes it slow down
Place or object used to determine if an object is in motion
What is reference point?
Name an example of a contact force?
Friction, air resistance, or water resistance
Occurs when one force acting on an object is stronger than the other
What is unbalanced force?
For every action, there is an equal and opposite reaction
Newton's Third Law
•When you take a step, you exert force against Earth. Does Earth exert a force against your foot? Explain.
Yes, equal and opposite reaction
Time it takes an object to travel a certain distance
What is speed?
Name an example of non-contact forces
Gravity, electric, or magnetic
The greater the mass of the object, the smaller its change in motion will be for a given force
The same force will cause an object will small mass to accelerate more than an object with large mass
What is Newton's Second Law?
Suppose a train engine is pulling 10 cars. The last car becomes separated from the train. What happens to the motion of the rest of the train?
Train will increase speed because of Newton's Second Law. Less mass needs less force to move.
Any change in speed or direction
What is acceleration?
Force is measured in this unit
What are Newtons?
What is another name for Newton's First Law?
Inertia
An adult and a child are standing together in the middle of an ice rink. The child pushes away from the adult, and the child moves backward, while the adult moves in the opposite direction, but slower.
Why do the adult and child move in this way?
Newton's Third Law says that for every action, there is an equal and opposite reaction.
The adult moved slower because Newton's Second Law states that an object with greater mass will take more force to move.