Video Transcript
What distance would a car travelling at 171 kilometres per hour for 38 minutes cover?
The easiest way to answer a question like this is to use our speed–distance–time triangle. In this question, we’re given a speed of 171 kilometres per hour. We are also given a time of 38 minutes. We can therefore calculate the distance travelled by multiplying the speed or velocity by the time.
A common mistake here would be to multiply 171 by 38. However, we can’t do this. The speed is in kilometres per hour, but our time is in minutes. We know that 60 minutes is equal to one hour, so we need to convert 38 minutes into hours. To convert from minutes to hours, we can write the number of minutes as a fraction over 60. Therefore, 38 minutes is 38 over 60 hours. Whilst it is not essential in this case, we could simplify this fraction to 19 over 30 by dividing the numerator and denominator by two.
We can now calculate the distance that the car travels by multiplying 171 by 38 over 60. Typing this into our calculator gives us an answer of 108.3. A car travelling at a speed of 171 kilometres per hour for 38 minutes will cover a distance of 108.3 kilometres.
