If you're seeing this message, it means we're having trouble loading external resources on our website.

If you're behind a web filter, please make sure that the domains *.kastatic.org and *.kasandbox.org are unblocked.

# Linear velocity comparison from radius and angular velocity: Worked example

Linear velocity from the radius and angular velocity for two pumpkin catapults with different arm lengths.

## Want to join the conversation?

• Wait, so here, You are saying that the MAGNITUDE OF LINEAR VELOCITY is equal to SPEED. SPEED EQUALS DISTANCE over TIME, or in this case, the arc length, aka DISTANCE, over Time. My question is that isn't the LINEAR VELOCITY equal to DISPLACEMENT divided by the TIME, just disregarding the direction?
• I'm confused as to why we can calculate linear velocity at all if velocity is dependent on displacement (so it should be measured from the direct distance between the starting point and end point). Can someone explain?
• Sal is actually using the magnitude(without direction) of velocity which is speed(because speed has not direction),hence displacement is used.
(1 vote)
• I understand this. But what if you have, for example, angular acceleration in the small catapult (In the clockwise direction of course), while the largest catapult doesn't have angular acceleration? Wouldn't the speed of the small catapult eventually surpass the speed of the largest catapult?
Maybe my question is not related to this, because here we are talking about angular velocity, speed and radius, but that doubt crossed my mind
(1 vote)
• Is the velocity of trebuchets and catapults are either angular or linear? there is something unrecognize in my mind because I observed as the payloads travelled, definitely in the curved path.
(1 vote)
• When it goes in a arc-like motion, how do the forces on the pumpkin differ from in a linear motion?
Just curious.
(1 vote)
• maybe because ones direction is changing constantly and the other isnt?
(1 vote)
• last numerical answer is de reases by 2. shouldn't it be final frequency decreases by 1/2??
(1 vote)
• Respected Sir, at 2.30 you said that angular velocity w is equal to 2pi radians. how can it be 2pi radians. the catapult has not covered a final angle of 2pi.