It is important because if they deviate then they may not achieve accurate measurable results, also so they can document their work.
To solve this problem we must resort to the Work Theorem, internal energy and Heat transfer. Summarized in the first law of thermodynamics.

Where,
Q = Heat
U = Internal Energy
By reference system and nomenclature we know that the work done ON the system is taken negative and the heat extracted is also considered negative, therefore
Work is done ON the system
Heat is extracted FROM the system
Therefore the value of the Work done on the system is -158.0J
Answer: An example of a non-renewable would be oil.
Explanation:
All fossil fuels are nonrenewable, but not all nonrenewable energy sources are fossil fuels. Coal, crude oil, and natural gas are all considered fossil fuels
A. 2 C₂ H₆ + 7 O₂ → 4 C O₂ + 6 H₂ O
according to law of conservation of mass , the total mass of reactants side must be same as the total mass of product side. so we need to check if each atom in the equation has same number on both side of the equation or not.
in this equation , we have
4 atoms of carbon left and 4 atoms of carbon on right
12 atoms of hydrogen on left and 12 atoms of hydrogen on right
14 atoms of oxygen on left and 14 atoms of oxygen on right
Answer:
We know that force applied per unit area is called pressure.
Pressure = Force/ Area
When force is constant than pressure is inversely proportional to area.
1- Calculating the area of three face:
A1 = 20m x 10 m =200 Square meter
A2 = 10 mx 5 m = 50 Square meter
A3 = 20m x 5 m = 100 Square meter
Therefore A1 is maximum and A2 is minimum.
2- Calculate pressure:
P = F/ A1 = 30 / 200 = 0.15 Nm⁻² ( minimum pressure)
P = F / A2 = 30 / 50 = 0.6 Nm⁻² ( maximum pressure)
Hence greater the area less will be the pressure and vice versa.