Physics - Chapter 10: Energy, Work, and Simple Machines

Kinetic Energy

energy due to motion

Work Energy Theorem

The ___ states that the work done on an object is equal to the object’s change in kinetic energy

Efficiency

Ratio of output work to the input work

Joule

SI unit of work

Watt

Unit of power equal to 1 J of energy transferred in 1 s

Work

The product of the applied force and the distance through which the force is applied

Energy

The ability of an object to produce a change in itself or its surrondings

Power

Rate of doing work

Machine

Device that changes the magnitude or direction of a force

Ideal Mechanical Advantage (IMA)

Ratio of effort distance to resistance distance

Mechanical Advantage (MA)

Ratio of resistance force to effort force

Compound Machine

A device that consists of two or more simple machines

System

Defined group of objects

Environment does work on a system…

energy increases

System does work on environment…

energy decreases

Kinetic Energy Equation

K=1/2mv²

Work Formula

W=Fd(cos(theta))

Change in Kinetic Energy

Change in K=W

Power Equation

P=W/t

Input Work

Work you do

Output Work

Work the machine does

Effort Force (Fe)

Force you exert

Resistance Force (Fr)

Force the machine exerts

Mechanical Advantage Formula

MA=Fr/Fe

Effort Distance (de)

Distance you move

Resistance Distance (dr)

The displacement of the object

Ideal Mechanical Advantage Formula

IMA=dr/de

Efficiency Formula

efficiency = MA/IMA * 100%

Six Simple Machines:

• Lever

• Pulley

• Wheel and Axle

• Inclined Plane

• Wedge

• Screw