VocabularyVocabulary

MachineMachine: any device that makes doing : any device that makes doing work easierwork easier

Mechanical advantageMechanical advantage: the # of times a : the # of times a machine multiplies the input force; machine multiplies the input force;

MAMA= output force/ input force= output force/ input force EfficiencyEfficiency: the percentage of the input : the percentage of the input

work done on a machine that the machine work done on a machine that the machine can return in output work; can return in output work;

EE=output work/input work =output work/input work ● 100● 100

VocabularyVocabulary

Simple machine: one of the basic Simple machine: one of the basic machines that makes doing work easier machines that makes doing work easier

1. lever1. lever2. Inclined plane2. Inclined plane3. Wheel and axle3. Wheel and axle4. Pulley4. Pulley5. Wedge5. Wedge6. Screw6. Screw

VocabularyVocabulary

Compound MachineCompound Machine: a machine that is made up : a machine that is made up of two or more simple machinesof two or more simple machines

NanotechnologyNanotechnology: the science and technology of : the science and technology of building electronic circuits and devices from building electronic circuits and devices from single atoms and moleculessingle atoms and molecules

RobotRobot: a machine that works automatically or by : a machine that works automatically or by remote controlremote control

FulcrumFulcrum: a fixed point around which a lever : a fixed point around which a lever rotatesrotates

LeverLever

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

Inclined PlaneInclined Plane

A simple machine A simple machine that is a sloping that is a sloping surface surface

Wheel and axleWheel and axle

A simple machine that A simple machine that is a wheel attached to is a wheel attached to a shaft, or axlea shaft, or axle

PulleyPulley

A wheel with a A wheel with a grooved rim that turns grooved rim that turns on an axleon an axle

WedgeWedge

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

ScrewScrew

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

Machines help people do workMachines help people do work

1.1. Machines change the way a force is Machines change the way a force is appliedapplied

a.a. If a machine decreases the amount of If a machine decreases the amount of force needed to do the work, the force needed to do the work, the distance over which that force must be distance over which that force must be applied increases.applied increases.

b.b. A machine can change the direction of A machine can change the direction of an applied forcean applied force

Input forceInput force: the force exerted on a : the force exerted on a machine.machine.

Output forceOutput force: the force exerted on an : the force exerted on an object by a machineobject by a machine

The number of times the machine The number of times the machine multiplies the input force is the machine’s multiplies the input force is the machine’s mechanical advantagemechanical advantage

2. Work transfers energy2. Work transfers energy

a. A machine increases the potential or a. A machine increases the potential or kinetic energy of an object by doing work on kinetic energy of an object by doing work on it.it.

b. For a certain amount of work, if distance b. For a certain amount of work, if distance increases, force decreases.increases, force decreases.

3. Output work is always less than input 3. Output work is always less than input workwork

a. Efficiency a. Efficiency

(output work/input work (output work/input work ● 100)● 100)

b. No real machine is 100 % efficient. b. No real machine is 100 % efficient.

c. Machines lose energy due to frictionc. Machines lose energy due to friction

d. Machines lose energy due to air d. Machines lose energy due to air resistance (car design, helmet design, resistance (car design, helmet design, airplane design)airplane design)

4. The mechanical advantage (MA) of a machine 4. The mechanical advantage (MA) of a machine can be calculatedcan be calculated(MA= Output force/Input force)(MA= Output force/Input force)

5. Modern technology uses 5. Modern technology uses compound machinescompound machines (machines made up of two or more simple (machines made up of two or more simple machines)machines)

6. Modern technology creates new uses for 6. Modern technology creates new uses for machinesmachinesa. nanotechnology (building with atoms and a. nanotechnology (building with atoms and molecules)molecules)b. robotsb. robots

Simple Machine 2 examples of where these machines can be found

Lever 1.2.

Inclined Plane 1.2.

Wheel & Axle 1.2.

Pulley 1.2.

Wedge 1.2.

Screw 1.2.