Question

Duncan takes a break from studying and goes to the gym to swim laps. If swimming burns 7.25×105 cal per hour, how many kilojoules does swimming burn in that same amount of time?
In other words, convert 7.25×105 cal to kilojoules.

Answer 1

As 1 cal = 4.184 × 10^-3 kJ:

7.25 × 10⁵ cal = 7.25 ×10⁵ cal × 4.184 10^-3 kJ = 30.334 × 10² kJ = 3033.4 kJ

Answer: 3033.4 kilojoules