Friction
Two types of kinetic friction
Sliding and Rolling kinetic friction
An object at rest remains at rest, and an object in motion remains in motion at constant speed and in a straight line unless acted on by an unbalanced force.
Newton's First Law
The force that pulls you toward your pencil is the force of ____
Gravity
When gravity is the only force acting on an object, the object is in _ _ _ _ _ _ _ _
Free Fall
A push or a pull
Force
When a force is applied to an object but does not cause the object to move
Static friction
What is Newton's first law sometimes called
Law of Inertia
How does the law of universal gravitation explain why astronauts on the moon bounce when they walk?
Newton;s third law states that objects exert ___ and ____ forces on each other.
Equal and Opposite
Any change in motion is caused by a ____
Force
Friction between moving surfaces
Kinetic friction
The acceleration of an object depends on the mass of the object and the amount of force applied.
Newton's Second Law
Newton summarized his ideas about gravity in a law now called ______
Law of Universal Gravitation
A moving object's ____ depends on the object's mass and velocity
Momentum
The force that opposes motion between two surfaces that are in contact is ______
Friction
What are two factors that affect the amount of friction between two surfaces?
Roughness and Force
Which of Newton's laws of motion describes the motion of an object that has a net force of 0
First Law of Motion
The closer one has more gravitational pull on each other and the other one is decreasing the gravitational pull on each other.
The fluid friction that opposes the motion of objects through air is known as _ _ _ _ _ _ _ _ _ _ _ _ _
Air Resistance
Force is expressed by a unit called _____
Newtons
The tendency of an object to resist being moved or, if the object is moving, to resist a change in speed or direction until an outside force acts on the object.
Inertia
Whenever one object exerts a force on a second object, the second object exerts an equal and opposite force on the first
Newton's Third Law
All objects in the universe attract each other through gravitational force.
Law of Universal Gravitation
The velocity at which a falling object travels when the force of air resistance exactly matches the downward force of gravity is called the _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
Terminal Velocity
The force of attraction between two objects that is due to their masses is _____
Gravity