Answer:
The diameter of the hose is 0.326 mm.
Step-by-step explanation:
Given that,
Speed of car = 28 miles/galllon
We need to calculate the radius
The rate of flow of fluid is from the equation of continuity

Where, A = area of cross sectional

We know that,
The velocity is the ratio of displacement of gas per unit time.


Put the value into the formula



We need to calculate the diameter of the hose

Put the value of r


Hence, The diameter of the hose is 0.326 mm.