Energy Debriefing

Welcome to the Energy debriefing

Answer the questions below. If necessary, click on the Check buttons when you are ready.

An electric space heater draws power from a wall outlet. When turned on, it heats the room it is in.

1. Which of the following is the best choice for the system?
		A. Power outlet
		B. Heater
		C. Room
Correct! The heater is the cause of the change that takes place in the problem, so it is the best choice for the system. Is that the best choice? What object is of primary interest in the problem? What causes most of the change that is described in the problem? The heater is the cause of the change that takes place in the problem, so it is the best choice for the system.

2. Click on the verbs in the problem description (repeated below) that describe energy or work transfers into or out of the system. Then pick a positive or negative sign from the drop down menus for each of the processes you picked. (Note: you don't have to fill up all the spaces if you don't think there are that many energy or work transfers in the description.) An electric space heater draws power from a wall outlet. When turned on, it heats the room it is in.
	positive negative
	positive negative
	positive negative
	positive negative
	positive negative
	positive negative
Correct! You have identified the two transfers of energy or work and given them the correct signs. You have picked an object instead of a process involving the transfer of energy or work. Try again. Is energy or work entering or leaving the system? What sign should it have? Correct! But is there another transfer you have overlooked? You have picked the correct energy and work transfers, but at least one of the signs is wrong. Try again.

Congratulations!

You have completed the Energy module.

Click on the Thermodynamics icon below to return to the Thermodynamics Gateway page.