Question

The gas tank on the back of a tanker truck can be equated to a cylinder with a diameter of 8 feet and a length of 19 feet. A gallon of gas is approximately 231 cubic inches. The density of the gasoline is .0262 pounds per cubic inch. The driver has stopped at a local farm to fill a tank that has linear dimensions that are 2/3 the size of his tank. If the driver's tank was full and the farmer's tank was empty, what is the mass of the gasoline in each of the tanks after the smaller tank is full?

Answer 1

9514 1404 393

Answer:

• driver's tank: 30,427 lb
• farmer's tank: 12,811 lb

Step-by-step explanation:

The formula for the volume of a cylinder is ...

  V = πr^2·h . . . radius r, height h

The radius of the driver's tank is half its diameter, so is (8 ft)/2 = 4 ft. Then the volume of that tank is ...

  V = π(4 ft)^2·(19 ft) = 304π ft^3

Each cubic foot of gasoline has a mass of ...

  (1728 in^3/ft^3)(0.0262 lb/in^3) = 45.2736 lb/ft^3

Then the total mass in the driver's full tank is ...

  (304π ft^3)(45.2736 lb/ft^3) ≈ 43,238.3 lb

__

The farmer's tank is a scaled-down version of the driver's tank. It's volume will be scaled by the cube of the linear scale factor, so will be (2/3)^3 = 8/27 of the volume of the driver's tank.

The farmer's tank will hold a mass of (43,238.3 lb)(8/27) ≈ 12,811 lb.

The amount remaining in the driver's tank is 43,238 -12,811 = 30,427 lb.