A diesel engine performs
35000 J of mechanical work and discards 45000 J of heat each cycle.
The heat supplied to the engine in each cycle is ()
A: 10000J
B: 45000J
C: 25000J
D: 80000J
35000 J of mechanical work and discards 45000 J of heat each cycle.
The heat supplied to the engine in each cycle is ()
A: 10000J
B: 45000J
C: 25000J
D: 80000J
举一反三
- A Carnot refrigerator is operated between two reservoirs and the cold<br/>reservoirs is at temperature of 270K. If in each cycle the<br/>refrigerator receives 415 J of heat energy from the reservoir at 270K<br/>and 77 J work is needed to be done on the working substance. The<br/>quantity of the heat energy delivered to the hot reservoir is (). A: 90J B: 338 J C: 492J D: 578J
- DU = 100 J is for a system that gives off 100 J of heat and ( ) A: does no work B: does 200 J of work C: has 100 J of work done on it D: has 200 J of work done on it.
- One mole of hydrogen with an initial temperature of 27℃ expands<br/>and in the process, absorbs 4000 J of heat and does 3000 J of work,<br/>the<br/>final temperature of the gas is () A: 62.3℃ B: 105.6℃ C: 75.1℃ D: 56.3℃
- A<br/>gas enclosed in a cylinder by means of a piston that can move without<br/>friction is warmed, and 1000 J of heat enters the gas. Assuming that<br/>the volume of the gas is constant, the change in the internal energy<br/>of the gas is [] A: 0 B: 1000<br/>J C: -1000<br/>J D: None<br/>of the above
- An engine converts 5,000 J of thermal energy into 2,500 J of work. What is the efficiency of the engine? A: 10 percent B: 20 percent C: 50 percent D: 100 percent