Question

An adult eats food whose nutritional energy totals

approximately2.2*103 Cal per day. The adult
burns2.0*103 Cal per day. How much excess
nutritionalenergy, in kilojoules, does the adult consume per day?
If 1lb of fat is stored by the body for each
14.6*103kilojoules of excess nutritional energy
consumed, how long will ittake this person to gain 1 lb.

Answer 1

An adult who consumes an excess of 0.2 x 10³ Cal per day, equivalent to 0.8368 x 10³ kJ, will gain 1 lb of fat in approximately 17.5 days, as 1 lb of fat is stored for each 14.6 x 10³ kJ of excess nutritional energy consumed.

Step-by-step explanation:

An adult consumes approximately 2.2 x 10³ Calories (Cal) per day and burns 2.0 x 10³ Cal per day. To find the excess nutritional energy in kilojoules, we need to subtract the energy burned from the energy consumed and then convert the result from Calories to kilojoules:

Excess energy (Cal) = 2.2 x 10³ Cal - 2.0 x 10³ Cal = 0.2 x 10³ Cal

Excess energy (kJ) = 0.2 x 10³ Cal x 4.184 kJ/Cal = 0.8368 x 10³ kJ

To calculate how long it will take for the adult to gain 1 lb of fat, we divide the amount of kilojoules that corresponds to 1 lb of fat by the daily excess kilojoules:

Days to gain 1 lb = (14.6 x 10³ kJ per 1 lb) / (0.8368 x 10³ kJ/day)

Days to gain 1 lb = 17.4512 days

Therefore, it will take approximately 17.5 days for the adult to gain 1 lb of fat, given the daily excess of 0.2 x 10³ Cal.

Answer 2

0.8368 kiloJoules of an excess nutritional energy is consumed by an adult in a day.

It will take 17,447.41 days long to gain 1 lb of fat by this person.

Step-by-step explanation:

Calorie intake of an adult in a day =
`2.2* 10^3 calorie`

Calorie burnt by an adult in a day =
`2.0* 10^3 calorie`

Excess nutritional energy in day=

`(2.2* 10^3 calorie)-(2.0* 10^3 calorie)`

`=2.0* 10^2 calorie`

1 kcal = 4.184 kJ

So , 1000 cal = 4.184 kJ

`1 cal = 4.184* 10^(-3) kJ`

`2.0* 10^2 calorie=2.0* 10^2* 4.184* 10^(-3) kJ`

`=0.8368 kJ`

0.8368 kiloJoules of an excess nutritional energy is consumed by an adult in a day.

`14.6* 10^3` kilo joules of excess nutritional energy = 1 lb fat

The 1 kilo joule of excess nutritional energy =
`(1)/(14.6* 10^3)` lb fat

Excessive nutritional energy of an adult per day = 0.8368 kiloJoules

Amount of fat gained by an adult per day =

=
`0.8368 kiloJoules* (1)/(14.6* 10^3)=5.7315* 10^(-5) lb` of fat

In 1 day an adult gains =
`5.7315* 10^(-5) lb` of fat

Time taken to gain 1 lb fat:

`(1)/(5.7315* 10^(-5)) day=17,447.41 days`

It will take 17,447.41 days long to gain 1 lb of fat by this person.