Motion

Ideal Simple Machine

A simple machine with no friction

Mechanical Advantage

The amplification of a force by increasing the input distance in a simple machine. the output force divided by the input force = equals the input distance divided by the output distance. Ex: pushing refrigerator up a ramp

Electromagnetic Force

interactions (pushes and pulls) of electrically charged particles with other charged particles and magnetic poles. Ex: like charges repel, opposite charges attract

Position vs. Time Graph

A graph with position on the y-axis and time on the x-axis, the slope of the line equals speed

Wheel and Axle

A simple machine that is compromised of two attached wheels of different diameters. Ex: ceiling fan

Average Speed

A measure of how fast an object’s position changes, calculated from distance/time. Ex: 35mph

Newton’s First Law/Law of Inertia

The law that objects resist changes in their state of motion. Ex: a rolling bowling ball keeps moving at constant speed

Axle

A rod or bar connected to the center of a wheel that allows it to turn

Net Force

The vector sum of all forces acting on an object

Output

A result of input into a system. Ex: human shivering to increase temperature when it is cold

Position

The location of an object

Force (elementary)

A push or a pull on an object

Screw

A simple machine that is an inclined plane wound around a shaft. Ex: screw on light bulb

Direction

The orientation of the movement of an object, often in a compass direction. Ex: north, south, east, west

Displacement

The difference between the starting and ending point of an object. Ex: 25 meters, northeast

Velocity

An object’s speed and direction. Average velocity is calculated from displacement/time while instantaneous velocity has to be measured at a specific moment in time. Ex: 5m/s, north

Meters (m)

The unit for distance in the metric system. Ex: the pool was 6m deep

Simple Machine

A device that makes work easier by reducing the fore (but increasing the application distance) or reducing the distance (but increasing the force)

Fulcrum

The pivot point of a lever. Ex: rock as a pivot under a board

Acceleration vs. Time Graph

A graph with acceleration on the y-axis and time on the x-axis

Input

Something put into a system that causes change. Ex: temperature changes in environment

Speed vs. Time Graph

A graph with speed on the y-axis and time on the x-axis, the slope of the line equals acceleration

Strong Nuclear Force

A force that hold protons and neutrons together in the nucleus. Ex: fission and fusion

Distance

The length of the path traveled by an object. Ex: 25 meters

Wedge

A triangular simple machine that pushes objects apart and changes the direction and amount of the input force. Ex: knife

Pulley

A simple machine that can change the direction and size of a force. Ex: block and tackle

Inertia

The tendency to resist changes in a state of motion. Ex: objects at rest and objects in motion stay in motion

Newton’s Third Law

The law that for every action there is an equal and opposite reaction. Ex: if you release the bottom of a balloon, the air rushes out. This movement causes an equal and opposite reaction and the balloon moved up.

Gravitational Force

The force of attraction of all masses toward each other due to gravitational pull. Ex: earth pulls on moon

Lever

A simple machine with a fulcrum, an output force or weight, and an applied force. Ex: seesaw

Work

The process by which energy is changed in a system; calculated from the product of force and distance. The object must move for work to have been done. Ex: lifting weights

Inclined Plane

A simple machine that is a ramp with one end higher than the other. Ex: slide, loading ramp

Acceleration

A measure of how quickly something changes its speed or direction, calculated from change in velocity/time. Ex: slowing down, turn a corner

Newton’s Second Law

The law that greater masses require a greater force to achieve the same acceleration, F=ma. Ex: force needed to stop a bowling ball vs baseball rolling at the same speed

Mass

The amount of matter in an object, measured in grams (g) or kilograms (kg), in the SI system of units

Force

An interaction (push or pull) of one object with another that resists other forces or causes acceleration. Ex: there are only 4 kinds of forces, called universal (or fundamental) forces: gravitational, electromagnetic, strong nuclear, and weak nuclear

Weak Nuclear Force

Force that resists particle decay in the nucleus. Ex: radioactive decay