Force & Motion

Velocity

a measure of speed in a given direction

Force

an action that can change the motion of an object. A push or a pull is an example of a force.

Unbalanced Force

forces that are not opposite and equal. Forces that cause a change in motion

Balanced Force

forces that are opposite in direction and equal in size, cause no change in motion, and the net force equals 0.

Gravitational force

is a force between any two objects. The strength of the force is related to the mass of the objects and the distance between them.

Acceleration

is found by dividing the change in the velocity of the object by the change in time

Mechanical advantage

is the number of times a machine multiplies the effort force

Work

is the transfer of energy when an applied force moves an object over a distance. For work to be done the force applied must be in the same direction as the movement of the object and the object must move a certain distance. (W = Fd)

Simple Machines

machines that work with one movement. The 6 simple machines are lever, pulley, inclined plane, wedge, screw, and wheel and axle.

Terminal velocity

occurs when the force of air resistance becomes large enough to balances the force of gravity. At this instant in time, the net force is 0 Newtons; the object will stop accelerating.

Newton's 1st Law

states that an object at rest will stay at rest unless it is acted upon by an unbalanced force. An object in motion will continue to move in the same direction and with the same speed unless acted upon by an unbalanced force.

Newton's 3rd Law

states that forces occur as equal and opposite pairs. For every action force there is an equal and opposite reaction force.

Newton's 2nd Law

states that the acceleration, a, of an object is directly related to the net force, F, applied to the object and inversely related to the mass, m, of the object. Shown by F = ma

Motion

the act or process of changing position or place

Mass

the amount of matter in an object

Net Force

the combination of all of the forces acting on an object.

Speed

the distance an object moves per unit of time

Effort Force

the force applied to a simple machine

Weight

the force due to gravity-Equal to the product of the object's mass and the acceleration of gravity (w = mg). At the surface of Earth, the acceleration of gravity is 9.80 m / s² which is the constant used in the equation for g.

Resistance Force

the force exerted by the machine

Inertia

the tendency of an object to resist a change in motion

Newton

the unit used to measure force

Joule

the unit used to measure work

Frictional forces

work against motion