force
The push or pull on an object with mass causes it to change its velocity
sliding friction
opposes the movement between two contact surfaces that slide against each other
terminal velocity
the constant speed that a freely falling object eventually reaches when the resistance of the medium through which it is falling prevents further acceleration
momentum
the quantity of motion of a moving body, measured as a product of its mass and velocity
gravitational force
the force of attraction between all masses in the universe
newton
the SI unit of force. It is equal to the force that would give a mass of one kilogram an acceleration of one meter per second per second, and is equivalent to 100,000 dynes
rolling friction
resistance to motion by bodies that are in rolling contact
projectile motion
a form of motion experienced by an object or particle (a projectile) that is projected in a gravitational field
law of conservation of momentum
in an isolated system the total momentum of two or more bodies acting upon each other remains constant unless an external force is applied
centripetal force
a force that acts on a body moving in a circular path and is directed toward the center around which the body is moving
net force
the vector sum of forces acting on a particle or object
fluid friction
the friction between layers of a viscous fluid that are moving relative to each other
inertia
a property of matter by which it continues in its existing state of rest or uniform motion in a straight line, unless that state is changed by an external force
electromagnetic force
the fundamental force associated with electric and magnetic fields
friction
the resistance that one surface or object encounters when moving over another
air resistance
the forces that are in opposition to the relative motion of an object as it passes through the air
mass
quantitative measure of inertia, a fundamental property of all matter
strong nuclear force
the fundamental force of nature that holds protons and neutrons together in the atomic nucleus
static friction
the frictional force resists force that is applied to an object, and the object remains at rest until the force of static friction is overcome
gravity
the forces that are in opposition to the relative motion of an object as it passes through the air
weight
a body's relative mass or the quantity of matter contained by it, giving rise to a downward force; the heaviness of a person or thing
weak nuclear force
the force that allows protons to turn into neutrons and vice versa through beta decay