What is a force?
a push or a pull
How is force described?
by its magnitude and direction
What is the SI unit of a force?
What kind of forces acting on an object result in a net force and cause a change in the object's velocity?
Equal forces acting on one object in opposite directions are called?
What is friction?
a force the two surfaces exert on each other when they rub against each other
What two factors determine the strength of the friction?
the types of surfaces involved and how hard they push together
What are the four types of friction?
static, sliding, rolling, fluid
What is a force that pulls objects toward each other?
The amount of matter something has is called its?
The amount of gravity between two objects depends on their masses and the
distance between them
What is weight?
the force of gravity on an object
When only the force of gravity is acting on an object, the object is said to be in?
What is a type of fluid friction that acts on objects falling through air?
An elastic force that stretches or pulls matter is called?
What does Newton's first law of motion state?
An object will remain at rest or moving at a constant velocity unless it is acted upon by an unbalanced force.
The tendency of an object to resist a change in motion is known as?
How is acceleration calculated?
Net force divided by mass
What is Newton's second law of motion?
acceleration depends on the net force acting on the object and on the object's mass
What does Newton's third law of motion state?
For every action, there is an equal but opposite reaction
How is momentum calculated?
mass x velocity
What does the law of conservation of momentum state?
the total momentum of any group of objects remains the same unless outside forces act on the objects
What is a centripetal force?
a force that causes an object to move in a circular path
Why do satellites in orbit around Earth continuously fall toward Earth, but never hit it?
Earth is curved, so they travel around it.