Speed of spinning wheel?


by IniX
Tags: speed, spinning, wheel
IniX
IniX is offline
#1
May8-09, 09:25 AM
P: 5
How would I calculate the speed of a spinning wheel (using forces in Newton and anything else required)?
Phys.Org News Partner Physics news on Phys.org
Physicists consider implications of recent revelations about the universe's first light
Vacuum ultraviolet lamp of the future created in Japan
Grasp of SQUIDs dynamics facilitates eavesdropping
jtbell
jtbell is offline
#2
May8-09, 09:44 AM
Mentor
jtbell's Avatar
P: 11,252
How would you calculate the linear speed of an object moving in a straight line?

(seriously, we need more details about where you're starting from!)
IniX
IniX is offline
#3
May8-09, 10:08 AM
P: 5
Take a roulette wheel. How would you calculate the speed of the spinning when the roulette wheel is spinned from the middle (by hand)?

russ_watters
russ_watters is offline
#4
May8-09, 11:49 AM
Mentor
P: 22,007

Speed of spinning wheel?


You need the force, the point at which the force is applied (to get the torque), the duration for which the force is applied and the moment of inertia of the wheel.
IniX
IniX is offline
#5
May8-09, 12:10 PM
P: 5
Could you please give me an example?
Physics in The Netherlands have a couple of different declarations, but I'll figure it out with an example of your explanation.
rcgldr
rcgldr is offline
#6
May8-09, 01:43 PM
HW Helper
P: 6,929
The "speed" of a wheel is it's rate of rotation. The angular inertia depends on the distribution of mass around the center of rotation. Angular momentum is the angular rate of rotation (angular speed) times the angular inertia. If you want to know how fast the wheels perimeter is moving linearly, it's the angular speed in radians per second times the radius.
russ_watters
russ_watters is offline
#7
May8-09, 02:45 PM
Mentor
P: 22,007
T=f*L
s=a*t
a=T*I
So...
s=f*L*I*t

f=force
L=lever arm length
a=acceleration
s=speed
T=torque
t=time
I=moment of inertia

If i were setting up a problem for a first year engineering student to solve, it would require those equations (it may also include the appropriate equation for moment of inertia). But if you're actually interested in a real world situation, then this is probably nowhere near specific enough to help you. But without more information about the problem you are trying to solve, there isn't much we can do. For example, I have no idea what the moment of inertia of a roulette wheel is and no way to solve for it because the geometry of the wheel is irregular.


Register to reply

Related Discussions
translating velocity and angle into wheel speed (for a two wheel robot) Differential Equations 4
Spinning wheel and arrow Introductory Physics Homework 4
spinning wheel Introductory Physics Homework 2
Spinning wheel and light speed Special & General Relativity 12
spinning wheel problem Classical Physics 1