Answer:
Part A
The efficiency of the engine is 10%
Part B
The change in internal energy is 300 J
Part C
The change in volume is 1 m³ which is one cubic meter
Explanation:
Part A
Efficiency is defined as the ratio of energy output to energy input;
The given parameters are;
The distance the car is moved, d = 10 meters
The force which moves the car, F = 100 N
The amount of energy produced by the engine = 1,000 J
Therefore, we have;
The energy output to the car = The work done on the car = Force applied to the car, F × The distance the car moves, d;
∴ The energy output to the car by the engine = F × d = 100 N × 10 m = 1,000 J
The energy input from the engine = The energy produced by the engine = 10,000 J
The efficiency of the engine = (The energy output)/(The energy input)= 1,000J/10,00J = 0.1
The efficiency in percentage = 0.1 × 100 = 10 %
The efficiency of the engine = 10%
Part B
The amount of heat added to the substance, ΔQ = 1,000J
The amount of work the substance does on the atmosphere, W = 700 J
The change in internal energy, ΔU is given as follows;
ΔQ = W + ΔU
∴ ΔU = ΔQ - W
For the substance, we have;
The change in internal energy, ΔU = 1,000 J - 700 J = 300 J
Part C
The work done by the piston, W = 1,000 J
The pressure, in the piston, P = 1,000 Pa = constant
The work done by the piston in a constant pressure process, W = P × ΔV
Where;
W = The work done
P = The constant pressure applied
ΔV = The change in volume = V₂ - V₁
V₂ = The final volume
V₁ = The initial volume
∴The change in volume ΔV = W/P = 1,000 J/(1,000Pa) = 1 m³
The change in volume ΔV = 1 m³
