ENERGY AND WORKFriction or Fact

Friction

Friction: is a force that opposes work

CAN BE USEFUL

Helps us turn and stop.

Football example

SENTEO QUESTION!

FrictionFriction makes Efficiency of Machines to Decrease!

Efficiency of Machines: tells you now much energy how much of the energy you put into the machine was transfered to the load.

Efficiency = Work done by the Load Force x 100%Work done by the Effort Force

SENTEO QUESTION

EnergyKinetic Energy is the Energy of motion.

the FASTER something moves the more Kinetic Energy it has.

Potential Energy is the stored energy.

Fats and Sugars store energy as chemical potential energy.

If you move a object to a high place you are storing energy in the form of gravitational potential energy.

SENTEO QUESTION

Energy can be transferred from potential to kinetic and back again.

REMEMBER the steel balls

The Right Machine for the Right Person

The science of designing machines to suit people is called ergonomics

Many machines are changed to suit people with needs beyond what the machine can do.