How Do Unit Conversion Errors Impact Fuel Calculations for Flight 143?

[chiraganand]

Homework Statement

Calculate various fuel quantities for Flight 143. The plane already had 7682 L of fuel ob board prior to flight and tanks were to be filled so that a total of 22300 kg were present at takeoff

(a) Using the incorrect conversion factor of 1.77 kg/L calculate in kg the amount of fuel that was added to the plane
(b) Using the correct conversion factor of 1.77 lb/L calculate in kg the amount of fuel that was added to the plane
(c) By what percentage would the plane have been underfueled

Homework Equations

No relevant equations as it is a simple conversion of units

The Attempt at a Solution

Solution for (a) was attempted by multiplying the existing fuel and subtracting it from the total amount of fuel .. answer was 8702 kg fuel needed
(b) was attempted by converting the total amount into Newtons by multiplying 9.81 and then converted to pound.. the answer found was 16134 kg

Can someone please verify and let me know if the answers are correct

 

[CWatters]

I got roughly the same answers but I didn't do b) the same way.

I converted 7682 L to 13579 Lbs then converted that to 6168kg (using 1kg = 2.2Lbs). Then subtracted 6168 from 22300 to give 16132 kg. I see no need to involve g.

 

[chiraganand]

sorry for sounding a little ignorant but wt does lbs stand for?

 

[Mark44]

sorry for sounding a little ignorant but wt does lbs stand for?

lbs = pounds

This is an unusual abbreviation since there are no letters in the abbreviation (lb) that are also in the word that is abbreviated (pound). The origin of the abbreviation is the Latin word libra, a measure of weight about the same as one pound.

 

[rezeew]

or not?

I would first like to point out that it is important to use the correct units when solving problems in science. In this case, the incorrect conversion factor of 1.77 kg/L was used, which led to incorrect calculations.

For part (a), the correct approach would be to convert the given 7682 L of fuel to kilograms by multiplying it by the correct conversion factor of 1 kg/L. This gives us 7682 kg of fuel. Then, we can subtract this from the total amount of fuel at takeoff (22300 kg) to get the amount of fuel added, which is 14618 kg.

For part (b), the correct conversion factor to use is 1 lb/L, not 1.77 lb/L. Using this, we can convert the given 7682 L of fuel to pounds by multiplying it by 1 lb/L. This gives us 16998 lb. Then, we can convert this to kilograms by dividing by the conversion factor of 2.205 lb/kg. This gives us 7713 kg of fuel. Again, we can subtract this from the total amount at takeoff to get the amount of fuel added, which is 14587 kg.

For part (c), we can calculate the percentage of underfueled by dividing the difference between the actual amount of fuel at takeoff (22300 kg) and the calculated amount of fuel needed (14587 kg) by the actual amount of fuel at takeoff. This gives us a percentage of 34.5% underfueled.

In conclusion, it is important to use the correct units and conversion factors when solving problems in science. Using incorrect units can lead to incorrect calculations and potentially affect the outcome of experiments or real-life situations.