Ask the apprentice to compute the volume of the liquid in a rectangular tank.

• Measure the inside dimensions (length, width and actual depth of the liquid) to the nearest eighth of an inch.

• Multiply length, width and height to get volume in cubic inches.
  V = L x W x D = 10 x 15 3/4 x 28 = 4410 in³
• Convert the volume in in3 to ft3, lb and gal. (Assume that the liquid is distilled water.)

  There are 12" x 12" x 12" = 1728 in³ so the volume in cubic feet is V = (4410 in³) ÷ (1728 in³) = 2.552 ft³.

  One cubic foot of water weighs 62.4 pounds so Weight = (2.552 ft³) x (62.4 lb/ f^t3) = 159.25 pounds.

  The volume can be converted to gallons using (159.25 lb) ÷ (8.34 lb/gal) = 19.1 gallons.
  
  

• Calculate the weight of the liquid in the tank if it were oil with a specific gravity of 0.9233.

  159.25 lb x 0.9233 = 147.04 pounds