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Objective: Student will learn how to compute work and power. Chapter 14 Section 1: 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
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Objective: Student will learn how to compute work and power. Chapter 14 Section 1: 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
Objective: Student will learn all the types of simple machines and how they move. Chapter 14 Section 3: Using Machines
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