weeerk - unit 8

Until now, we have been learning about work, or any change in energy. Today we learned about power, and how that is the result of work divided by time. The units are joules/sec, also known as a watt. During our laboratory, we learned that objects that are more massive take more power to move. This is because the rate at which work is being done is greater than the rate of an object that is less massive. The difference between work and power, is that work is the amount of energy an object uses, and power is the rate of the energy being used.

The cost of electricity is about 20c/ Kwh, the following equation is the cost of one light bulb left on for ten hours straight.

0.21 Kw * 10 hrs * 0.20 c/Kw hr = $0.42