Download Chapter 4 Motion and Forces Vocabulary

From 7th grade book: Chapter 4 Motion and Forces Vocabulary
Force-A push or pull exerted on an object
Net force-The overall force on an object when all the individual forces acting on an
object are added together.
Unbalanced force-A nonzero net force that changes an object’s motion.
Balanced force-Equal forces acting on an object in opposite directions.
Inertia-The tendency of a moving object to continue in a straight line or of a stationary
object to remain in place.
Newton-A unit of measure that equals the force required to accelerate one kilogram of
mass at a rate of one meter per second per second.
Friction-A force that one surface exerts on another when the two rub against each other.
Sliding friction- the kind of friction that results when you rub sandpaper against wood
Rolling friction- the kind of friction that results when a wheel turns on a surface.
Fluid friction- the kind of friction that results between oil and a door hinge.
Gravity-The force that pulls objects toward each other.
Freefall-The motion of a falling object when the only force acting on it is gravity.
Projectile-An object that is thrown.
Air resistance-The fluid friction experienced by objects falling through air.
Terminal velocity-The maximum velocity a falling object achieves.
Law of universal gravitation -The law that states that the force of gravity acts between
all objects in the universe.
Momentum-The product of an object’s mass and velocity.
Law of conservation of momentum-The rule that the total momentum of objects in an
interaction does not change
Pressure-The force that something exerts over a given area; also, the force exerted on a
surface divided by the total area over which the force is exerted.
Equilibrium-A state in which opposing forces in a system are equally balanced or stable.