4. The blades on a fan have a frequency of 15 Hz.
a) How many cycles do the blades complete in five minutes?
b) What is the period for the fan blades?
c) How long would it take for the fan blades to complete 100 revolutions?

6–55 refrigerant-134a enters the condenser of a residential heat pump at 800 kpa and 358c at a rate of 0.018 kg/s and leaves at 800 kpa as a saturated liquid. if the compressor consumes 1.2 kw of power, determine (a) the cop of the heat pump and (b) the rate of heat absorption from the outside air.

Gasoline comes from petroleum, which is made from ancient living things. petroleum, therefore, contains a type of energy. a. heat b. nuclear c. biological d. chemical potential

The ozone hole appears in antarctica during