In my opinion the answer is B. Variation
Answer:Both are correct
Explanation:
Both are correct because
Mechanical efficiency is the dimensionless term which is the ratio of brake horsepower to the Indicated horse Power
Where brake power is the Power obtained at the crankshaft and
Indicated horsepower is the power obtained in the combustion chamber and this power is the loss in the form of friction.
Volumetric efficiency is the ratio of actual fuel intake to the maximum air fuel that could be taken.
Given:
Work done, W = 5 J
Initial energy = 8J
Final energy = 30J
Let's determine if the work done have a positive or nrgative value.
Appy the equation for the first lae of thermodynamics:

Where:
U is the change in internal energy
Q is the added heat
W is the work done
To find the work done here, we have:
Rewrite the formula for W

Where:
ΔU = 30J - 8J = 22J
Q = 5J
Thus, we have:

Therefore, the work done here is -17J.
This means the work done in this scenario has a negative value.
ANSWER:
The work done in this scenario has a negative value
Answer: 75 ft
Explanation:
Breaking distance = Speed²/ 20
= 30²/20
= 45 feet
Stopping distance = Speed + braking distance
= 30 + 45
= 75 ft
Answer:
density describes how much space an object or substance takes up (its volume) in relation to the amount of matter in that object or substance (its
mass). In maths and physics density is calculated as mass defined as mass divided by volume (Density = Mass ÷ Volume).