### Author Topic: Constant speed circular motion  (Read 17673 times)

#### Fu-Kwun Hwang

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##### Constant speed circular motion
« on: July 27, 2008, 09:16:57 am »
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A particle is under acceleration when it's speed changed over time.
When a particle is moving around a circle with constant speed.
The velocity is changed constantly. The direction of the velocity vector is changing with time. (Velocity is a vector.)

You can click Play to start the simulation and click pause to stop it.
More information will be displayed when the simulation is paused.
When the simulation is paused at time t: The RED arrow shows the velocity vector at that time.
Another vector in Magenta shows its velocity at previous time step t-dt.
(The starting point for the above two vector is different)

We also draw those two vectors again from the same starting point (which is the center of the circle).
You can find out the difference between two vectors (GREEN vector).

Click STEP button to make the time step forward and watch the differences.
I hope this applet can help you understand why acceleration is required for constant speed circular motion.

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#### Fu-Kwun Hwang

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##### Re: Constant speed circular motion
« Reply #1 on: February 27, 2009, 12:50:45 am »
Here is another applet about circular motion.
It was designed to illustrate relation/constraint for circular motion: a=V2/R.

Red arrow is the instance velocity \$V(t)\$,
arrow with color "magenta" is \$V(t+dt)\$
The blue arrow is \$dvec{V}=vec{V}(t+dt)-vec{V}(t)\$ which is always pointing toward the center.
with  \$d   heta=V*dt/R\$ ,
so It's length \$|dvec{V}|=V d   heta=V* V*dt/R\$,
so \$frac{dvec{V}}{dt}=frac{V^2}{R}\$

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#### crestiksa

• Posts: -2
##### Constant speed circular motion
« Reply #2 on: November 01, 2009, 08:56:17 pm »
Subject: RE: RE: Was Constant Speed - I/O 390 engine performance ?
I had the hartzel C/S that vans sells for the 200 horse engine. I would
gladly use it again or step up to the new blended airfoil one when it is
available. The MTs sure are pretty. -*-

#### lookang

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##### Re: Constant speed circular motion
« Reply #3 on: April 16, 2016, 12:19:25 am »