Angular motion-centrifuge problem .

[Prashant91]

Homework Statement

: A centrifuge starts from rest and speeds up at 3400rpm after 50 seconds.

a sample is at a distance of 37.5mm from the centre

1) find the angular acceleration
2) calculate the centripetal acceleration [/B]

Homework Equations

:

v2 / r

v = rω

a = rω2

a=Λω/Λt

3. The Attempt at a Solution

1) a=Λω/Λt = 3400/60*2∏/50 = 7.12 rad/sec^2

2) a_c =v^2/ r = 7.12/ 0.01875 ( 0.01875 is the radius converted to M) [/B]

 

[AlephNumbers]

0.01875 is the radius converted to M

sample is at a distance of 37.5mm from the centre

The distance from the center of the circle to a point on the circumference of the circle is the radius of the circle. So wouldn't the radius of the circle be 37.5mm? Which, converted to meters, is .0375?

 

[BvU]

In addition: $v^2$ is not 7.12 rad/s²

 

[BvU]

In addition: $v^2$ is not 7.12 rad/s²