simple algebra question: Achilles and a tortoise were racing on a 1 km track. Achilles runs on a constant 8 m/s speed and the tortoise's speed is 0.8 m/s. Halfway through the track, Achilles decided to take a nap since the tortoise was so far behind. However, when he woke up, the tortoise was already near the finish line. Achilles started to run again with constant speed of 8 m/s, but he lost to the tortoise by 3 seconds. How long did Achilles sleep? Note: Let the tortoise and Achilles' speed be constant
I think I can solve it. 1km = 1000m?
yes. i think so
18.8 minutes
any solutions to prove?
I will be assuming that 1km = 1000m. So, halfway through the track, Achilles took a nap. Halfway through the track is 5km or 500m. It took Achilles about 62.5s, or 1 minute and 2.5 seconds. Hmm. So he lost to the tortoise by 3 seconds. So tortoise won by 3 second, with a speed of 0.8m/s. |dw:1373112344612:dw|
Harder than I thought...
indeed it is :)
tortoise time : 1000/.8 = 1250 achilles time : 1253 achilles sleep = 1253 - 1000/8
that gives 18.8 minutes.. just a short nap lol
"achilles time : 1253"? How did you get that?
Join our real-time social learning platform and learn together with your friends!