In: Physics
1. A centrifuge rotor is accelerated for 28. s from 9000 rpm to 17000 rpm (revolutions per minute).
(a) What is its average angular acceleration?
2. A centrifuge rotor is accelerated for 20. s from 7000 rpm to 15000 rpm (revolutions per minute).
(a) What is its average angular acceleration?
1.
Using 1st rotational kinematic equation:
wf = wi + *t
= (wf - wi)/t
wi = Initial angular velocity = 9000 rpm = 9000*2*pi/60 = 942.48 rad/sec
wf = final angular velocity = 17000 rpm = 17000*2*pi/60 = 1780.24 rad/sec
t = 28 sec
So,
= (1780.24 - 942.48)/28
= 29.92 rad/sec^2 = 30.0 rad/sec^2 = average angular acceleration
1.
Using 1st rotational kinematic equation:
wf = wi + *t
= (wf - wi)/t
wi = Initial angular velocity = 7000 rpm = 7000*2*pi/60 = 733.04 rad/sec
wf = final angular velocity = 15000 rpm = 15000*2*pi/60 = 1570.8 rad/sec
t = 20 sec
So,
= (1570.8 - 733.04)/20
= 41.888 rad/sec^2 = 41.9 rad/sec^2 = average angular acceleration
Let me know if you've any query.