Question

A runner burns 3.51×103kJ during a five-mile run. How many nutritional Calories did the runner burn?

Answer 1

Answer: The runner burnt 14.625 cal.

Explanation: KiloJoule and Calories are two unit of energy.

To convert kJ in cal:

1kJ = 0.24Kcal

3.51.10³ kJ = x

x =
`(3.51.10^(3) )/(0.24)`

x = 14.625.10³ Kcal

However, it is asked for calories, not kilocalories. So, to find that it is only needed to divide the number by 1000 or multiply by
`10^(-3)`:

14.625.10³.
`10^(-3)` = 14.625 cal

The runner burn 14.625 nutritional calories.