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
Answer: The dependent Variables include: Size and Types of trees.
The independent Variables include:
geographic elevations that is, valleys and the higher elevations.
Explanation:
The dependent variable simply refers to the variable a researcher tests or measures during an experiment. On the other hand, the independent variable simply refers to the variable that's controlled during an experiment.
Based on the definition above, the dependent variables include the size and the types of trees while the independent variables include the
geographic elevations that is, the valleys and the higher elevations.
2.22 m/s. Average speed is Total distance over time it took. 100m/45s = 2.22m/s