Which physical law underlies the first law of thermodynamics? Which physical law underlies the first law of thermodynamics? conservation of matter increase in entropy conservation of energy conservation of work Request Answer Part B The quantity Q is the that is added to the system. The quantity is the that is added to the system. heat work entropy internal energy Request Answer Part C The quantity W in the first law refers to the . View Available Hint(s) The quantity in the first law refers to the . work done on the system work done by the system change of energy in the system change of volume in the system Part D The quantity ΔU in the first law of thermodynamics is the change in the of the system. Choose the correct option. Choose the correct option. entropy internal energy heat energy temperature Request Answer

The complete question is;

The first law of thermodynamics is usually written as

Q=W+?U.

You need to look at the signs carefully; some other disciplines (chemistry, for example) may use other signs, which implies other definitions of these quantities.

1-Which physical law underlies the first law of thermodynamics?

-conservation of matter

-increase in entropy

-conservation of energy

-conservation of work

2- The quantity Q is the that is added to the system.

-heat

- work

-entropy

-internal energy

3-The quantity W in the first law refers to the .

-work done on the system

-work done by the system

-change of energy in the system

-change of volume in the system

4)The quantity ΔU in the first law of thermodynamics is the change in the of the system.

-entropy

-internal energy

-heat energy

-temperature

1) Otption C - conservation of energy

2) Option A - Heat

3)Option B - work done by the system

4)Option B - Internal energy

Explanation:

The first law of thermodynamics which is actually based on the principle of conservation of energy states that the change in internal energy of a system equals the net heat transfer into the system minus the net work done by the system. In equation form, the first law of thermodynamics is ΔU = Q − W.

Thus, from this definition, we can answer the questions;

1)Option C - Conservation of Energy

2) Q is the heat added to the system. - Option A

3) W is the work done by the system

4)ΔU is the change in the internal energy of the system.

b) phosphorus pentoxide

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 =