Chapter 14 Section 1: Work and Power Objective: Student will learn how to compute work and power.

Work Work is done when a force causes an object to move in the same direction that they force is applied. Draw/ write the captions for figure 2 on page 427. The equation for finding work is Work (in joules) = force (in newtons) x distance (meters) W=Fd

Power Power is rate at which work is done. The equation for power is Power ( in watts) = work (joules)/ time (seconds) P= W/t

Chapter 14 Section 3: Using Machines Objective: Student will learn all the types of simple machines and how they move.

Simple Machine A simple machine is a machine that does work with only one movement. A machine made up of a combination on simple machines is a compound machine. There are six simple machines: inclined plane, lever, wheel and axle, screw, wedge, and pulley.

Inclined Plane An inclined plane is a flat, sloped surface. Less force is needed to move an object from one height to another using an inclined plane. Examples: ramps, hills

Wedge An inclined plane that moves is a wedge. Examples: knives, axes, teeth

Screw A screw is an inclined plane wrapped around a post or a cylinder. Friction between the threads allows for objects to “hold.”

Lever A lever is an rigid rod or plank that pivots, or rotates, about a point. The point about which the lever pivots is called a fulcrum. Examples, see saws, crowbar, spatula

Wheel and Axel A wheel and axel is two circular objects of different diameters attached so that they rotate together. Examples: water faucets, rotary telephone, rolling pin, pencil shapener

Pulley A pulley consist of a grooved wheel with a rope or cable wrapped over it. Example: flag pole, blinds, curtain on window