Answer:
a) , For m kilograms, it is 4184m J., 3600000 joules, b)
Explanation:
a) The amount of heat needed to warm water is given by the following expression:
Where:
- Mass of water, measured in kilograms.
- Specific heat of water, measured in
.
,
- Initial and final temperatures, measured in
.
Then,
The energy needed in kilowatt-hours is:
The electric energy required to heat up the water is:
Lastly, the cost of heating a hot tub is: (USD - US dollars)
The heat needed to raise the temperature a degree of a kilogram of water is 4184 J. For m kilograms, it is 4184m J. Besides, a kilowatt-hour is equal to 3600000 joules.
b) The current required for the electric heater is: