Math at the Race Track
We have the privilege of living in a town that has access to a small speedway. My boys are big car fans and this year we felt everyone was finally old enough to enjoy watching some races. One thing you may not know about me is that I am married to an engineer. Math is a way of life at our house! It comes up often and we are constantly curious about how our day is affected by math. A day at the races is no exception! Within 30 minutes, my 10 year old wanted to know how fast the cars were going. The speedway had no stat for miles per hour posted on the big sign. My husband and I went right into math mode. How he explained the answer and the way I explained the answer were slightly different.
My Husband's Explanation:
First, he asked for my iPhone. He used my stop clock to calculate the speed of a singular car around the track. This track is 1/4 mile long. He timed the same car three times around the track. They averaged 15 seconds. 4 laps to 1 minute for 1 mile, thus averaging 60 mph.
When I heard the question, my mind instantly went to distance formula–which I knew could be changed to rate formula!
.25 mile/15 seconds = Rate
I knew I would need to do some conversions and my mind went to ratios.
.25 mile/15 seconds = 1 mile/60 seconds
1 mile/60 seconds which can be written as 1 mile per minute, thus the car is going 60 miles per hour!
Both valid ways of explaining how to calculate the rate of the car.
Looking for a fun way to calculate rate?
Head over to the Meridian Speedway's website and look at real lap times from this year! Select a race, then a car, and download a PDF of lap times. You could have students look up information together and answer questions like:
- How fast was the first place car going? Second? Third?
- Compare the times between a qualifying race and a Sprint Dash. Were their times similar? By how many seconds did their laps differ?
- Look at a race with more laps than 4. Was the driver able to sustain a similar speed towards the end of the race? Graph the lap times for each lap. Do you see a trend?