Ch.5 Work, Energy, and Power

Work done

Force x distance moved in direction of force.

(In Joules)

Power

The rate at which work is done. (In Watts)

P=Energy/time

P=Force x Velocity

Kinetic energy formula

(In Joules)

Potential energy

Stored energy that results from the position or shape of an object (In Joules)

PE= mgh

Energy

The ability to do work (in Joules)

Efficiency

The percentage of the input work that is converted to output work.

Useful energy or power/Total energy or Power times 100

Derive KE Formula

Derive GPE Formula

Derive P=Fv

Joule

The force that would give a mass of one kilogram an acceleration of one meter per second squared in the direction of the force.

Finding "g=9.81" in an experiment.

1. Use a meter stick to measure the height an object is to be dropped

2. Drop an object with initial “u” velocity of zero.

3. Use a stopwatch. Measure the time it takes the object to hit the

Ground.

4. Plug in height “s”, time “t”, and “u = 0” into the equation s=ut +1/2at^2

.

5. Solve for “a”. This should give you “g” after many trials and

averaging

Gravitational potential energy definition.

Energy stored due to an object due to its position in a gravitational field.

Conservation of Mechanical energy