Question

It takes Serina 3.36 hours to drive to school. Her route is 18 km long. What is Serina's average speed on her drive to school?

Answer 1

1.49 m/s

Step-by-step explanation:

The average speed is:

`\displaystyle{v_{\sf{average}} = \frac{s_{\sf{total}}}{t_{\sf{total}}}}`

Where v is speed, s is distance and t is time. We are given with a distance of 18 km and time is 3.36 hours.

We'll be converting from km to meters and hours to seconds as standard unit for speed is m/s.

To convert the unit from kilometer to meter, we know that 1 kilometer equals to 1000 meters. Therefore, 18 kilometers will equal to 1000 * 18 meters which will equal to 18000 meters total.

To convert from hour to second, we know that 1 hour equals to 60 minutes. Therefore, 3.36 hours will equal to 60 * 3.36 = 201.6 minutes.

A minute equals to 60 seconds. Therefore, 201.6 minutes equal to 60 * 201.6 = 12096 seconds.

Finally, we have units in meter and second. We'll be able to calculate for average speed now by applying the formula above:

`\displaystyle{v_{\sf{average}} = (18000)/(12096)}\\\\\displaystyle{v_{\sf{average}} = 1.49 \ \, \sf{m/s}}`

Therefore, Serina's average speed will be around 1.49 m/s