An insulated piston–cylinder device contains 100 l of air at 400 kpa and 25°c. a paddle wheel within the cylinder is rotated until 15 kj of work is done on the air while the pressure is held constant. determine the final temperature of the air. neglect the energy stored in the paddle wheel. (page 172).

What is the length x of the side of the triangle below? (hint: use the cosine function)

Which type of energy would have nothing to do with ironing clothes? a. heat b. chemical c. electrical d. mechanical

The heater element of a 120 v toaster is a 5.4 m length of nichrome wire, whose diameter is 0.48 mm. the resistivity of nichrome at the operating temperature of the toaster is 1.3 × 10-6 ω·m. the toaster is operated at a voltage of 120 v. (a) what is the power drawn by the toaster? (b) if the cost of electricity is 12 ¢ per kilowatt-hour, and it takes 2 minutes to toast bread, how much does it cost for toasted bread? (c) when the heater element is at room temperature, is the resistivity in the nichrome wire greater than, less than, or equal to it’s resistivity when at operating temperature? explain.