Force, Motion, Work, Power & Simple Machines Vocabulary- SHMS

Comprehensive vocabulary and definitions for physics concepts including kinematics, dynamics, and simple machines.

Acceleration

The change in velocity over time, measured in $m/s^2$.

$$m/s^2$$

The unit for acceleration.

Force

A push or a pull on an object that may cause a change in motion, such as making an object stop, start moving, or change direction.

Friction

A force that opposes motion between two surfaces that are touching.

Gravity

The force of attraction between objects due to their masses.

Motion

A change in position over time when compared to a reference point.

Inertia

The tendency of an object to resist changes in motion; it depends on mass.

Work

Using a force to move an object over a distance, where the force and movement need to be in the same direction.

Net Force

The force that results from combining all of the forces exerted on an object.

Speed

The distance traveled in a certain amount of time, measured in $m/s$.

$$m/s$$

The unit for speed.

Velocity

The distance traveled over time in a particular direction; the same as speed but with a direction.

$$m/s + \text{direction}$$

The unit for velocity.

Weight

The measure of the gravitational force exerted on an object, measured in newtons ($N$).

Compound Machine

A machine made up of 2 or more simple machines, such as a can opener, scissors, or zipper.

Inclined Plane

A straight slanted surface that reduces the force required but applies it over a larger distance.

Lever

A bar that pivots at a fixed point called the fulcrum.

Mechanical Advantage

Describes how many TIMES the machine MULTIPLIES the force applied, calculated as $MA = \frac{\text{output force}}{\text{input force}}$, with no units.

Power

The rate at which work is done (how fast work is done), calculated as $P = \frac{w}{t}$ and measured in watts ($W$).

Pulley

A grooved wheel that holds a rope; it may be fixed or moveable and changes the DIRECTION of the applied force.

Screw

An inclined plane wrapped in a spiral where a small force is applied over a very large distance.

Wedge

A double inclined plane that MOVES, used for cutting, such as a knife, axe head, or chisel.

Wheel & Axle

A machine consisting of a larger wheel rigidly attached to a smaller cylindrical rod called the axle.