A cylinder with height 8 and radius 4. An ant walks across this cylinder along the shortest path on the curved surface from the top corner to the bottom corner on the other side (opposite side of the cylinder). What is the distance that the ant travels?
Distance across cylinder
0
$\begingroup$
algebra-precalculus
-
0Unroll. Trace. Calculate. Profit. – 2012-03-23
2 Answers
3
Your cylinder can be thought of as a rolled up rectangle, with height $8$ and width $8\pi$. So your distance will be $\sqrt{(8^2)+(4\pi)^2}.$
Edited: Misread the problem in the first go. Since the ant will end up on the opposite side in the bottom, he is going "down 8" and "over $4\pi$."
-
0I edited my response. I slightly misread the original problem. – 2012-03-21
0
Hint: you can cut the cylinder with a vertical line and unroll it to make it flat. Now what is the shortest path? How long is it?
-
0@Ross Yes he does. – 2012-03-23