# calulating the power that can be safely transfered by ashaft?

• Dec 6th 2010, 11:15 AM
Jamesy81
calulating the power that can be safely transfered by ashaft?
Hi.

This is the question i have been given on my progress check. Calualte the power that can be safely transferred by a 100mm shaft rotating at 150 revoulutions per minute?

I have been trying to find a forumla for this but i have hit dead ends. Can any one shed any light on the matter

Thanks alot
• Dec 7th 2010, 08:18 AM
BabyMilo
Im not sure if this would help.

P=Fv
where P=power
F=Force
v=velocity.

F=w^2r
r= radius of the shaft ie (100*10^-3)/2
w=2pi*f
w=v/r to find v
where f is the frequency ie 150 rev/mins
convert that to rev/s

can you finish?
• Dec 7th 2010, 04:49 PM
skeeter
$P = \tau \cdot \omega$
• Dec 8th 2010, 10:20 AM
Jamesy81
Quote:

Originally Posted by skeeter
$P = \tau \cdot \omega$

Thanks for replying if power = time x work how am i meant to get the power using the 100mm measurement and the revolutions? i may just be acting stupid?
• Dec 8th 2010, 01:47 PM
skeeter
Quote:

Originally Posted by Jamesy81
Thanks for replying if power = time x work how am i meant to get the power using the 100mm measurement and the revolutions? i may just be acting stupid?

not time x work ... it's the product of torque and angular velocity.