Answer:
a) 3.242
b) 1291.178 KJ
c) 3.59 cents
Explanation:
a) First all the temperature units should be in Kelvin. -30°C + 273.15 = 243.15K and 45°C + 273.15 = 318.15K. Coefficient of performance for refrigerator is COP = TL/(TH-TL) where TL is Lower Temperature and TH is the Higher Temperature. COP = 243.15/(318.15-243.15) = 3.242
b) COP = Cooling Effect/Work Input. Cooling Effect (or Desired Output) is 4186 kJ.
So Work Input = Cooling Effect/COP = 4186KJ/3.242= 1291.178 KJ
c) 3.6 MJ (3600kJ) is for 10 cents, using ratio for cost: energy used
3.59 cents
The distance between two nodes is HALF the wavelength. So if the wavelength is 2cm the distance between two adjacent nodes is 1 cm. does this help?
Answer: B. The south magnetic pole attracts the north pole of another magnet.
Explanation:
The correct statement below about the interaction between magnets, magnetic materials and charges is that the south magnetic pole attracts the north pole of another magnet.
We should note that a magnet typically consists of two poles which are the North Pole and the South pole. The opposite poles doesn't repel each other but attracts each other while same pole repels one another.
In this case, the North Pole will attract the South Pole while same magnetic piles repel e.g the North Pole will repel the North Pole.