Question

You drive in canada where the distance are marked in kilometers. The sign says you are 80km from Ottawa. You are at a speed of 75mi/h. Would you reach Ottawa within one hour, after one hour or later than hour?

Answer 1

Since 1 mile is approximately 1.609 km we would expect that the speed of 75 mi/h is higher if we measure it in km/h. Since the distance is 80 km, we should calculate the time as less than one hour, which can be confirmed if we use a conversion factor:

$80\,km \Big( \cfrac{1\,mi}{1.609\,km} \times \cfrac{1\,h}{75\,mi} \Big)=0.663\,h$

In conclusion, we would reach Ottawa within one hour.

Reference

• Chang, R., & Goldsby, K. A. (2010). Chemistry. Chemistry, 10th ed.; McGraw-Hill Education: New York, NY, USA.