Vocabulary  Machine: any device that makes doing work easier  Mechanical advantage: the # of times a machine multiplies the input force;  MA= output force/ input force  Efficiency: the percentage of the input work done on a machine that the machine can return in output work;  E=output work/input work ● 100

Vocabulary  Simple machine: one of the basic machines that makes doing work easier 1. lever 2. Inclined plane 3. Wheel and axle 4. Pulley 5. Wedge 6. Screw

Vocabulary  Compound Machine: a machine that is made up of two or more simple machines  Nanotechnology: the science and technology of building electronic circuits and devices from single atoms and molecules  Robot: a machine that works automatically or by remote control  Fulcrum: a fixed point around which a lever rotates

Lever  A solid bar that rotates, or turns, around a fixed point (fulcrum);

Inclined Plane  A simple machine that is a sloping surface

Wheel and axle  A simple machine that is a wheel attached to a shaft, or axle

Pulley  A wheel with a grooved rim that turns on an axle

Wedge  A simple machine that has a thick end and a thin end; used to cut, split, or pierce objects, or hold objects together

Screw  A simple machine that is an inclined plane wrapped around a cylinder; used to raise and lower weights as well as to fasten objects

Machines help people do work 1. Machines change the way a force is applied a.If a machine decreases the amount of force needed to do the work, the distance over which that force must be applied increases. b.A machine can change the direction of an applied force

 Input force: the force exerted on a machine.  Output force: the force exerted on an object by a machine  The number of times the machine multiplies the input force is the machine’s mechanical advantage

2. Work transfers energy a. A machine increases the potential or kinetic energy of an object by doing work on it. b. For a certain amount of work, if distance increases, force decreases.

3. Output work is always less than input work a. Efficiency (output work/input work ● 100) b. No real machine is 100 % efficient. c. Machines lose energy due to friction d. Machines lose energy due to air resistance (car design, helmet design, airplane design)

4. The mechanical advantage (MA) of a machine can be calculated (MA= Output force/Input force) 5. Modern technology uses compound machines (machines made up of two or more simple machines) 6. Modern technology creates new uses for machines a. nanotechnology (building with atoms and molecules) b. robots

Simple Machine2 examples of where these machines can be found Lever1. 2. Inclined Plane1. 2. Wheel & Axle1. 2. Pulley1. 2. Wedge1. 2. Screw1. 2.