Fuel Consumption - P-2030070

FUEL CONSUMPTION

Solving problems of fuel consumption is similar to problems of speed, time, or distance.

Both are rate problems. The only difference is that the unit that changes over a given

amount of time is now fuel instead of distance. Again, it is a simple matter of setting up

ratios on the computer and solving for the unknown factor. The outer scale is now used as

the FUEL scale; and the solution is still a matter of transferring the ratio, or proportion, to

the outer/inner scales of the computer and reading the unknown factor (fuel consumed or

rate of consumption). Use the formula:

FUEL FL OW FUEL CO NSUMED

RATE INDEX

TIME

Since fuel is measured in pounds, the outer scale on the CR-3 becomes the FUEL (in

pounds) scale while the inner scale remains the TIME scale.

Examples of fuel consumption problems follow.

EXAMPLE ONE:

Finding amount of fuel consumed.

Given: Fuel consumption. . . . . . . . . . . . . . 1000 pounds per hour

Time flown. . . . . . . . . . . . . . . . . . . .1 hour and 45 minutes

Find:

Fuel consumed

Solution:

1. Estimate the answer. Since the total time is just under 2 hours the answer should be

a little under 2000 (2 hr x 1000 # / hr), approximately 1800.

2. Place the RATE INDEX (▲) located on the TIME (inner) scale under the 10 (1000 #

/ hr) on the FUEL (outer) scale. (Figure 4.3-24)

Figure 4.3-24 Fuel Consumption 1

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