Ten seconds is 1/6 of a minute and 1 minute is 1/60 of an hour, so 10 seconds is 1/360 of an hour.
If you graph her trip with the speed on the y-axis and the time on the x-axis, you get a triangle with height of 60 mph and width of 1/360 of an hour. To calculate the area of the triangle, you multiply 1/2 × 1/360 × 60 = 1/12.
The answer cannot be determined. 60mph is a rate of speed. The answer infers that each second the car gains 6mph. However the riddle does not specifically state that the car gains speed at a consistent rate . It says the car “constantly accelerates”, which means that it’s gains can fluctuate over time so long as they are gaining. Therefore in order for the answer to the riddle to be correct. The riddle would need to have its verbiage changed from saying “constantly accelerating” to “consistently accelerating”. Also her car doesn’t hook & book very well so the author might want to consider getting a faster car for Debbie if your gonna call it a dragster.
Debbie starts driving her dragster from rest and constantly accelerates to 60 mph in 10 seconds. How far does she travel in those 10 seconds?
Answer: »
1/12 mile
Ten seconds is 1/6 of a minute and 1 minute is 1/60 of an hour, so 10 seconds is 1/360 of an hour.
If you graph her trip with the speed on the y-axis and the time on the x-axis, you get a triangle with height of 60 mph and width of 1/360 of an hour. To calculate the area of the triangle, you multiply 1/2 × 1/360 × 60 = 1/12.
Assuming her speed was constant, which it was not! She started from rest.
60mph, is 1mile/minute( unbelievably slow for a “Dragster” )?
By my reckoning: In 10 secs she would have travelled 1/6 of a mile: approx. 293 yards?
6 Comments on "Debbie’s Dragster"
kelechi says
May 20, 2016 @ 11:54
6 miles
froggie123 says
May 24, 2016 @ 01:50
?! I did not get that one at all!
Ellie says
October 27, 2017 @ 09:57
Too many math riddles. My brain does not like numbers!
Michael A says
November 15, 2019 @ 18:18
The answer cannot be determined. 60mph is a rate of speed. The answer infers that each second the car gains 6mph. However the riddle does not specifically state that the car gains speed at a consistent rate . It says the car “constantly accelerates”, which means that it’s gains can fluctuate over time so long as they are gaining. Therefore in order for the answer to the riddle to be correct. The riddle would need to have its verbiage changed from saying “constantly accelerating” to “consistently accelerating”. Also her car doesn’t hook & book very well so the author might want to consider getting a faster car for Debbie if your gonna call it a dragster.
Mark W says
February 16, 2025 @ 20:07
Hi Dan,
Regarding the following puzzle.
Debbie starts driving her dragster from rest and constantly accelerates to 60 mph in 10 seconds. How far does she travel in those 10 seconds?
Answer: »
1/12 mile
Ten seconds is 1/6 of a minute and 1 minute is 1/60 of an hour, so 10 seconds is 1/360 of an hour.
If you graph her trip with the speed on the y-axis and the time on the x-axis, you get a triangle with height of 60 mph and width of 1/360 of an hour. To calculate the area of the triangle, you multiply 1/2 × 1/360 × 60 = 1/12.
Assuming her speed was constant, which it was not! She started from rest.
60mph, is 1mile/minute( unbelievably slow for a “Dragster” )?
By my reckoning: In 10 secs she would have travelled 1/6 of a mile: approx. 293 yards?
Dan says
February 17, 2025 @ 12:17
Let me solve this step by step.
First, let’s identify what we know:
Initial velocity (u) = 0 mph (starting from rest)
Final velocity (v) = 60 mph
Time (t) = 10 seconds
We need to find distance (s)
Let’s convert 60 mph to feet per second:
60 mph = 60 × (5280 feet/mile) ÷ (3600 seconds/hour)
60 mph = 88 feet per second
Since acceleration is constant, we can use the equation:
Distance = (initial velocity × time) + (½ × acceleration × time²)
Or s = ut + ½at²
We can find acceleration using v = u + at:
88 = 0 + a(10)
a = 8.8 ft/s²
Now we can plug into the distance equation:
s = (0 × 10) + (½ × 8.8 × 10²)
s = 0 + (½ × 8.8 × 100)
s = 440 feet
Therefore, Debbie travels 440 feet in 10 seconds, or 1/12th of a mile.
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