Simple Machines

Simple Machine:

A machine that does work with only one motion. They change the direction or amount of force in order to make work easier. They don’t create force, they only transform it.

Work

When a force moves an object or changes its position.

Formula for Work (Work triangle)

Force (N) X distance (m)

Formula for Force

Work (J)/ distance (m)

Formula for distance

Work (J)/Force (N)

Input Force

The force supplied to a machine in order to work.

Output Force

The force that the machine creates when the input force is supplied.

Power

The rate at which work is done or the amount of work per unit of time.

Formula for Power

Work (J)/time (s)

Formula for Work (Power Triangle)

Power (W) X time (s)

Formula for time

Work (J)/ Power (W)

The 6 Basic Simple Machines

Screw, Lever, Inclined Plane, Wedge, Pulley, Wheel and Axle

Mechanical Advantage

How much a machine changes the input force.

Three parts of a lever

Fulcrum, Load, and Effort

First Class Lever

A lever where the fulcrum is placed between the load and effort. In these levers, the further away from the fulcrum you apply the force, the easier it is to lift up the object.

Second Class Lever

A lever where the load is between the effort and the fulcrum. In these levers, the effort always travels a large distance and is less than the load.

Third Class Lever

A lever where the effort is between the fulcrum and the load. In these levers, the effort always travels a similar distance and must be a greater than the load.

Inclined Plane

A simple machine that consists of a sloping surface connecting a lower position to a higher position.

3 Forces of an inclined plane

Gravity, Normal Force, Friction

Screw

A simple machine made by wrapping an inclined plane around a cylinder.

Wheel & Axle

A simple machine consisting of a cylinder or rod attached to the center of a large wheel so that they rotate together.

Wedge

A triangular shaped object with two sloping sides. A wedge changes the direction of the input force.

Pulley

A pulley is a grooved wheel with a rope running along a grove.

Fixed Pulley

A type of pulley that changes only the direction of your force and has a mechanical advantage of 1.

Moveable Pulley

A type of pulley that changes the amount of force but not the direction and has a mechanical advantage of 2.

Compound Pulley

A type of pulley that changes the amount and direction of the force and has a mechanical advantage of 2.

Energy

The ability to do work

The two types of energy

Potential and Kinetic energy

Chemical Potential Energy

Energy stored up because of what an object is made up of. When an organism consumes another organism, it takes their chemical energy.

Gravitational Potential Energy

The energy objects that are high above the ground are said to have.

Kinetic Energy

Energy that has motion. Objects can turn any potential energy into kinetic energy.

Law of Conservation of Energy

Energy can’t be created or destroyed, only transformed.

Elastic Energy

Energy that is stored up when an object changes shape.

Total Mechanical Energy

The sum of an objects kinetic and potential energy.

Gravitational Potential Energy Factors

Height, Mass, Gravity

Formula for GPE

Mass x Gravity x Height

Units for Energy

Joule/J

Kinetic Energy Factos

Velocity, Mass

Formula for KE

½ m x v²