Question

The nutritional calorie (Calorie) is equivalent to 1 kcal. One pound of body fat is equivalent to about 4.1 x 103 Calories. If a runner expends 1850 kJ/h, how long (h) does she have to run to work off 7.56 lb of body fat? Enter your answer in decimal format with one decimal place.

Answer 1

`t = 70.13 hours`

Step-by-step explanation:

As we know that 1 lb fat can be used to expend 4.1 k Calorie of energy

so here we know that we have to use 7.56 lb of body fat

so here the total energy that is to be utilized is given as

`Q = (4.1 * 10^3)(7.56)`

so we will have

`Q = 30996 Calorie`

now we know that runner expends the energy at rate of 1850 kJ/h

so we have

`E = 1850 * 10^3 kJ/h`

so it is

`E = 0.44 * 10^3 calorie/h`

now we know that time to burn this energy is given as

`t = (Q)/(E)`

`t = (30996)/(0.44 * 10^3)`

`t = 70.13 hours`