<p>You know that ride at some theme parks, where you have those swings attached to a big rotating center machine. When the ride goes faster, the swings gradually move up and become parrallel with ground.</p>
<p>Why does that happen? According to sparknotes when the swings spin counter-clockwise the angular acceleration is upward. This could be the answer but the swings would still go upward if spun clockwise (angular acceleration would then be downward) , so I really don't know.</p>
<p>It's called UCM - uniform circular motion (see: <a href="http://www.physicsclassroom.com/mmedia/circmot/ucm.html%5B/url%5D">http://www.physicsclassroom.com/mmedia/circmot/ucm.html</a>)</p>
<p>Centripetal force is the force experienced by the moving object that's directed towards the center of the circle - although, in this case, it's where the swings are attached to the moving platform. Furthermore, the faster the swings move, the stronger the centripetal force. The centripetal force is also upwards, since attachment is above the seats of the swings.</p>
<p>So, greater speed --> stronger centripetal force --> more upward force --> counteracts gravity more --> rises higher.</p>
<p>I have no clue why they're talking about clockwise and counterclockwise.</p>
<p>Don't hold me up to this, though. I hate physics :P.</p>
<p>parallel? do you mean perpendicular? if it's parallel wouldn't the riders simply be flung out? since there is no centripetal force keeping them in circular motion. i think sparknotes has it right but i don't think you really understand the direction of the angular acceleration. i'm going to assume that the ride is perpendicular to the ground so when the ride spins faster the centripetal force is greater so the frictional force is greater(since the centripetal force points towards the center of the ride and is parallel to the ground). this frictional force is pointing upward since it is resisting the pull of gravity (assuming you're not in space) and if it's fast enough you "stick" to the sides of the ride</p>