Question

Use these values: distance traveled is 30.0 km; time elapsed is 40.0 minutes; average power output is 370 watts. Determine the total energy expended by the cyclist, in kilojoules.

Answer 1

Explanation:

It is known that the relation between power and work is as follows.

           Power = $\frac{\text{work done}}{Time}$

As it is given that power is 370 watts and time is 40 minutes. First, we will convert minutes into seconds as follows.

               $40 min \times \frac{60 sec}{1 min}$

                 = 2400 sec

Now, total power or energy is calculated as follows.

              Power = $\frac{\text{work done}}{Time}$

                         = $\frac{370 watts}{2400 sec}$        

                         = 888000 J

As 1 kJ = 1000 J. So, convert 888000 J into kJ as follows.

                 $\frac{888000}{1000} kJ$

                  = 888 kJ

therefore, we can conclude that total energy expended by the cyclist is 888 kJ.