Simple Machines Review

Simple Machines

A simple machine is a mechanical device that changes the direction or magnitude of a force.

Six Simple Machines

• Lever

• Wheel and Axle

• Inclined Plane

• Wedge

• Screw

• Pulley

Lever

A lever is a straight or curved rigid bar that is free to turn about a fixed point.

All levers have three location of interest:

• Fulcrum or Fixed Point

• Point of Effort where work is done on the lever

• Load which is being moved

Classes of Lever

• Class 1 Lever

• Class 2 Lever

• Class 3 Lever

Class 1 Lever

has fulcrum located between effort and load. Class 1 lever includes crowbar, scissors, and pliers.

Class 2 Lever

has the load between the effort and load. The effort and resistance move in the same directions. Examples of class 2 levers are wheel barrows, bottle opener, and nutcracker.

Class 3 Lever

has the effort between the load and the fulcrum. Effort and resistance move in the same direction. Fishing rod, tweezer, and tongs are examples of class 3 levers.

Pulley

A pulley is a grooved wheel that turns around and axle which is held in place by mounting bracket.

Inclined Plane

An inclined plane is a plane tilted at an angle, with one end higher than the other.

Screw

A screw is actually a spiral inclined plane. It is composed of a cylindrical body with a spiral ridge called thread. The treads surround the cylinder from the tip to the head. A screw increases the force but a longer distance.

Wheel and Axle

The wheel and axle is a machine that has a small disk or shaft called an axle that is attached to a wheel.

Wedge

A wedge is an inclined plane or two inclined planes that meet each other to form a sharp edge.

Multiple Choice

________________ is done whenever a force moves an object a distance.

• Load

• Friction

• Force

• Work

Multiple Choice

Which type simple machine would the base of a light bulb be?

• screw
• wedge
• wheel and axle
• pulley

Multiple Choice

The fixed point around which a lever rotates is know as the

• wheel.

• fulcrum.

• input force.

• output force.

Multiple Choice

A simple machine that splits an object apart is a _______.

• inclined plane

• fulcrum

• wedge

• lever

Multiple Choice

A ramp is an example of a(n) _______.

• inclined plane

• fulcrum

• force

• lever

Multiple Choice

What simple machine makes work easier by using a wheel and rope to help move an object?

• pulley

• wheel & axle

• inclined plane

Multiple Choice

What is this simple machine?

• Inclined Plane

• Lever

• Gear

• Wheel and axle

Multiple Choice

What type of simple machine is this?

• Pulley
• Screw
• Inclined Plane
• Lever

Multiple Choice

All simple machines help make work _________.

• harder
• smaller
• lighter
• easier

Multiple Select

how many types of levers are there?

• 1

• 2

• 3

• 4

• 5

Multiple Choice

Which type of simple machine is not found in scissors?

• Wedge

• Pulley

• Lever

Multiple Choice

Whenever a force moves something it is called...

• Power

• Work

• Pressure

• Heat

Multiple Choice

A measure of how quickly work is being done is called...

• Force

• Work

• Energy

• Power

Multiple Choice

Two or more simple machines that operate together form what?

• A compound machine

• A replacement

• A reaction

• A simple machine

Multiple Choice

The work done to lift an object is...

• Weight x Distance

• Distance x Height

• Weight x Length

• Length x Distance

Multiple Choice

What is stored energy?

• Kinetic energy

• Potential energy

• Mechanical energy

• Electrical energy

Multiple Choice

What is energy of an object in motion?

• Potential energy

• Kinetic energy

• Mechanical energy

• Electrical energy