Question

A family requires 20,000 KJ of fuel energy every day. If calorific vlaue

of the fuel used by them is 15,000 kJ/kg, how much of this fuel will be

required by this family to meet their energy needs for the month of April?​

Answer 1

40 kilograms of fuel are required to meet their energy needs for the month of April.

Step-by-step explanation:

The month of April has 30 days and the full energy needed by the family is determine by the following combustion formula, derived from dimension analysis:

`n\cdot Q = m\cdot L_(c)` (1)

Where:

`m` - Mass of the fuel, measured in kilograms.

`L_(c)` - Calorific value of the fuel, measured in kilojoules per kilogram.

`Q` - Daily fuel energy, measured in kilojoules.

`n` - Number of days of the month, dimensionless.

If we know that
`Q = 20000\,kJ`,
`n = 30` and
`L_(c) = 15000\,(kJ)/(kg)`, then the amount of fuel required to meet their energy needs for the month of April is:

`m = (n\cdot Q)/(L_(c))`

`m = ((30)\cdot (20000\,kJ))/(15000\,(kJ)/(kg) )`

`m = 40\,kg`

40 kilograms of fuel are required to meet their energy needs for the month of April.