500cm3 of water is to be jeated from room temperature 28oc to 100oc in order to prepare ahot cup pf coffee. What os the minimum heat required

The minimum heat required is 171626 joules.  

Explanation:

By First Law of Thermodynamics, the amount of heat (), in joules, is equal to the change in internal energy of water. The minimum heat required is the sensible heat necessary to heat up the water. That is:

(1)

Where:

- Density of water, in kilograms per cubic meter.

- Volume of water, in cubic meters.

- Specific heat of water, in joules per kilogram-degree Celsius.

- Change in temperature, in degrees Celsius.

If we know that , , and , then the minimum heat required is:

The minimum heat required is 171626 joules.  

need to see circuit to get time constant

their crystal patterns have been disrupted by stress