Simple Machines

Work

the transfer of energy to an object by using a force that causes the object to move in the

direction of the force

W = F x d

Think-Pair-Share

Select the activities below that require the least amount of work

-carrying heavy books home-reading a 300-page novel-skiing for 1 hour-lifting a 45 kg mass-holding a steel beam in place for 3 h-jacking up a car

Joule (J)

unit used to measure energy

Example: W = F x d

W = 80 N x 1 m80 (N x m)

80 J

Power

the rate at which work is done or energy is transformed

P = Work divided by timeP = W ÷ t

Measured in watts (W): the unit used to express power (equal to J/s)

What is a machine?• A machine is a

device that makes work easier by changing the size or direction of a force.

Simple Machines Foldable

• Using a foldable, you are going to:–Identify the six different types of

simple machines–Define each type of simple machine–Give two real-world examples of each

types of simple machine

1. Inclined Plane• ramp or slanting surface that

connects a lower level to a higher level

2. Lever• stiff bar that rest on a support called

a fulcrum

3. Pulley• grooved wheel with a rope or cable

around it

4. Screw• an inclined plane wrapped around a

pole

5. Wedge• slanting side

ending in a sharp point used to split, lift, or hold

6. Wheel and Axle• circular device with

a rod, called an axle, through its center

Complex Machines• Two or more simple machines that

work together to do work