Simple Machines, Power and Work

In Your Notes

What is a Simple Machine?

• Simple: easy to understand; not complex• Machine: a device that transfers force or

motion• Simple Machine: Any of the following six

devices: pulley, lever, inclined plane, wedge, screw, and wheel and axle

Pulley

• Uses grooved wheels and a rope to raise, lower, or move a load

Lever

• A stiff bar that rests on a fulcrum which lifts loads

Inclined Plane

• A slanting surface that connects a lower level to a higher level

Wedge

• An object with at least one slanting side and a sharp edge, which cuts material apart

Screw

• An inclined plane that wraps around a pole, which holds material together or lifts materials

Wheel and Axle

• A wheel with a rod, called an axle, that lifts or moves materials

All Six Simple Machines

Discuss with your partner other examples of simple machines in action

Work

• A force that acts on a body, causing a displacement.

• Work=Force x Displacement • Work is measured in joules

Power

• Amount of energy consumed in time• Power = Work/Time• Power is measured in watts