Question

Medals shall be rewarded. Thanks for the help
(Trigonometry question)

A Ferris wheel with radius 31m makes 2 rotations in one minute.

a) Find the angular velocity in radians per second.

b) How far has a rider traveled if the ride is 10 minutes long?

(I basically converted the 2 revolutions per minute in 0.21 rad/sec as the final answer for part (a), which is correct, but I am having trouble solving part (b)).

Answer 1

It makes 1 rotation in 30 seconds. That is 2pi radians in 30 seconds. So it goes 4 pi radians in 60 seconds. So a is:
\[\frac{4\pi}{60}=\frac{\pi}{15} radians per second\]

Answer 2

b) If the ferris wheel has a radius of 31 m, you can find its circumference. What is it?

Answer 3

According to the book I have, the distance is 974m

Answer 4

\[C=2\pi r=2(3.14)(31)=194.68 m\] in 1 revolution. So in 2 revolutions (1 minute) it goes 389.36 m.
And in 10 minutes, it goes 10(389.36) of 3893.6 m

Answer 5

That is the very answer I got as well. Maybe the book is wrong?

Answer 6

Either that or you have posted part b incorrectly.

Answer 7

Okay. Thank you very much.

Answer 8

Oh...you could double check the units. Are you sure it said 974 meters?

Answer 9

Yup. 974m.

Answer 10

Then it is incorrect.

Answer 11

Okay. Thanks again.

Answer 12

http://msmklein.wikispaces.com/file/view/2.Angular+velocity.pdf

Scroll down to page 3 and look at problem number 2. The solution is on page 4

Answer 13

Okay, the copy I received definitely has errors in it.

Answer 14

yep.