A hot object cools down according to Newton's Law so that t hours after the start, the rate that heat leaves is 57−/3 Joules per hour. How much heat leaves the object during the first 7 hours? [All you need to know is that a Joule is a quantity of heat. In fact, 4.2 Joules is the heat required to raise 1 gram of water 1 degree Celcius]

H = 154.41 J

Explanation:

given,

rate at which heat leaves

Heat leaves during first 7 hours

integrating both side

H = 154.41 J

Hence,heat the object during the first 7 hours is equal to 154.41 J.

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 =