Thermodynamics

The Eiffel Tower (made of iron) is 301 m high on a day when the temp is 22 °C, how much does its height decrease when the temperature cools to 0 °C?

-0.0795

An aluminum rod changes its length by 0.000032 m when the temperature changes by 120 K. What was the initial length of the aluminum rod?

0.011

A heat engine has a high temperature reservoir of 330 K and a low temperature reservoir at 260 K. What is the maximum efficiency of the engine?

0.212

What is the efficiency of an engine that exhausts 870 J of heat in the process of doing 340 J of Work?

0.39

A steam engine's boiler completely converts 155 kg of water to steam. This process involves the transfer of 3.5 x 108 J as heat. If steam escaping through a safety valve does 1.76 x 108 J of Work expanding against the outside atmosphere, what is the net change in the internal energy of the water-steam system?

1.74*10^8

How much thermal energy must be added to 960 g of water at 100 °C to make steam at 100°C?

2,169,600

A 25g mass of lead is heated from 23° to 100°C, how much heat energy did the lead absorb?

308

Suppose you have an ideal heat engine that can operate in one of two different modes. In mode 1 the temps of the two reservoirs are 200 K and 400 K. In mode 2 the temps are 400 K and 600 K. is the efficiency of mode 1 greater than, less than or equal to the efficiency of mode 2?

Mode 1 is greater than mode 2

A total of 135 J of Work is done on a gaseous refrigerant as it undergoes compression. If the internal energy of the gas increases by 114 J during the process, what is the total amount of energy transferred as heat? Has energy been added to or removed from the refrigerant as heat?

Q=-21

Both water and steam at 100°C and steam at 100°C can cause serious burns. Is a burn produced by steam likely to be more severe, less severe, or the same as a burn produced by water?

Steam as it takes more energy to condense