I have a couple of questions.(adsbygoogle = window.adsbygoogle || []).push({});

1. Assume that the function x(t) represents the length of tape that has unwound as a function of time. Find theta(t), the angle through which the drum will have rotated, as a function of time.

Express your answer (in radians) in terms of x(t) and any other given quantities.

There is a picture for this that I attached below. This question doesn't seem very difficult but I cannot think of a way to solve it. I know that the amount of tape unwound in one revolution is 2*pi*r but do not know how to relate this to x(t)

2. A magnetic computer disk 8.0 cm in diameter is initially at rest. A small dot is painted on the edge of the disk. The disk accelerates at 600 rad/s^2 for .5s, then coasts at a steady angular velocity for another .5s.

A.What is the speed of the dot at t = 1.0 s? This equals 12m/s

b. Through how many revolutions has it turned? This is the problem. I would think that you should find circumference of the circle and use the speed from part a to find the number of revolutions but this has not worked.

Any help would be greatly appreciated. Thanks

**Physics Forums - The Fusion of Science and Community**

# Need help(Rotation Problems)

Know someone interested in this topic? Share a link to this question via email,
Google+,
Twitter, or
Facebook

- Similar discussions for: Need help(Rotation Problems)

Loading...

**Physics Forums - The Fusion of Science and Community**