Energy

TYPES OF ENERGY TRANSFERS

Thermal, light, electrical, sound, kinetic, chemical, nuclear, Potential (Elastic and Gravitational)

Energy is conserved

Efficiency=useful output energy / total input energy

A light bulb is a representation of an Energy Transfers. 100j of Electrical Energy goes in. 20j of light comes out. 80j of Thermal comes out.

Enrgy transfers take place by conduction, convection or radiation

Convection is used in Everyday life to heat rooms. the convection currents move the heat around the room keping it warm

Anything that stops heat is insulative. it prevents the heat molecules moving through it and stops areas getting too hot

Work Done=force*distance moved

W=FxD

Gravitational potential Energy=Mass*g* height

GPE=MxGxH

Kinetic Energy= 1/2*mass*(speed*Speed)

KE=1/2xMxV2

the conservation of energy produces links between GPE, KE and Work

Power is the rate of transfer of energy or the rate of doing work

Power= Work Done/Time Taken

P=W/T

types of Energy resources= Wind, Water, Geothermal, Solar heating Systems

Fossil fuels, Solar Cells, Nuclear power

U=initial velocity

V= final velocity

a=acceleration

s=displacement

t=time

Average speed= distance/time

V=SxT

Acceleration=change in speed / time

A=(V-U) / T

v2=u2+2as

A force is a push or pull on an object

A vector is a force in a stated direction. A scalar is a force in any direction.

The force that opposes motion is friction

F=MxA

W=MxG

objects reach terminal velocity when air resitance and the speed is the same\

the factors that affect stopping distance are thinking distance and breaking distance

Moment of a force= force*perpendicular distance from pivot

mom= FxD

momentum of an object= mass *velocity

Momentum=MxV