The heating element of a water heater in an apartment building has a maximum power output of 30 kw. four residents of the building take showers at the same time, and each receives heated water at a volume flow rate of 1.49 10-4 m3/s. if the water going into the heater has a temperature of 10° c, what is the maximum possible temperature of the hot water that each showering resident receives

22.02°C

Explanation:

P = Power output = 30 kW

Volume flow rate of water =

S = Specific heat of water = 4.186 kJ/mol°C

= Initial temperature = 10°C

= Final temperature

Total volume of water is

Mass flow rate is

Heat is given by

The maximum possible temperature of the hot water that each showering resident receives is 22.02°C

it is given that trillions of microbes make up to 1% to 3% of the body mass.

let's take average of this percentage: 2%

consider the average mass of the human body as 70 kg.

then, trillions of microbes would have mass  

therefore, 100 trillion micro-organisms would weigh:

this is an approximate value and could change depending on the mass of the human body and percentage of the microbes present in it.

average mass per microorganism =