What Are Linear and Angular Velocity?Date: 09/16/2004 at 14:16:28 From: Sang-duk Subject: radians and linear and angular velocity confusion What exactly is linear and angular velocity? I know the formulas, s = rt and w = theta/r, but what do they mean? Date: 09/16/2004 at 15:36:21 From: Doctor Schwa Subject: Re: radians and linear and angular velocity confusion Hi Sang-duk, Linear velocity is how fast something moves: its distance divided by time. Angular velocity is how fast something turns: its angle moved divided by time. For example, when a CD is spinning in a CD player, suppose it spins 200 times per minute. Its angular velocity is 200 spins per minute, or 200*360 degrees per minute, or 200*2pi radians per minute, or 200*2pi/60 radians per second, or ... The CENTER of the CD has a linear velocity of zero: it's not going anywhere! If the edge is 6 cm away, then the edge of the CD spins (2pi * 6) = 12pi cm per spin, so the linear velocity is 2400pi cm/minute. Does that make sense? The angular velocity is (spins or degrees or radians) per minute while the linear velocity is (cm or m or feet or inches) per minute. Let me know if you still have questions! - Doctor Schwa, The Math Forum http://mathforum.org/dr.math/ |
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