While filling up your car with gasoline, you notice that it takes 3 minutes to dispense 55 liters of gasoline through the 2.5 cm diameter hose.What is the average speed, in m/s, of the gasoline inside the hose?
A)2.48
B)0.62
C)6.2
D)0.248

Question

Quizplus · Accepted Answer

We can use the formula for the volume flow rate of a liquid through a pipe:
Q = πr^2v
where Q is the volume flow rate, r is the radius of the pipe (which is half the diameter), and v is the speed of the liquid.
We know that the diameter of the hose is 2.5 cm, so the radius is 1.25 cm (or 0.0125 m).
We also know that it takes 3 minutes to dispense 55 liters of gasoline, which is equivalent to 0.917 liters per second (55 / 60 = 0.917).
So we can plug in the values we know and solve for v:
0.917 = π(0.0125)^2v
v = 0.62 m/s
Therefore, the average speed of the gasoline inside the hose is 0.62 m/s.

While Filling Up Your Car with Gasoline, You Notice That