Power:

Objectives:

    1.    Describe power and its measurements.

    2.    Explain the units of power.

    3.    Calculate power, work, and time using the formula; P = W/t.

Key Terms:

    power    watt

Resources:

    http://www.glenbrook.k12.il.us/gbssci/phys/Class/energy/energtoc.html

Notes:

Power:

Power indicates the rate (how fast) that work is being done.

It is the rate at which work is being done
It is not the amount of work rather the amount of work per unit time

            Formula:    Power = Work / time or P = J/s

Remember that the unit for work is the Joule and that the second is the unit for time
The unit for power is the Watt (W)

Horsepower:

In the 1760s, the most common source of power was the horse.  It was determined that the average horse could move a 750N object 1m/s.

Horsepower (hp) = P*750 = 750W/s