Adiesel engine performs 2100 j of mechanical work and discards 4500 j of heat each cycle. part a)
how much heat must be supplied to the engine in each cycle?
part b)
what is the thermal efficiency of the engine?

(a) 6600 J

(b) 31.8%

Explanation:

work performed, W = 2100 J

Heat discard, Q2 = 4500 J

(a) Let Q1 be the amount of heat supplied

Work = Q1 - Q2

Q1 = Q2 + W = 4500 + 2100 = 6600 J

(b) efficiency = 1 - Q2 / Q1

Efficiency = 1 - (4500 / 6600) = 0.318 = 31.8 %

c. newton's third law of motion

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 =