Please show work and complete answer. Thanks A centrifuge is a device in which a
ID: 2140944 • Letter: P
Question
Please show work and complete answer. Thanks
A centrifuge is a device in which a small container of material is rotated at a high speed on a circular path. Such a device is used in medical laboratories, for instance, to cause the more dense red blood cells to settle through the less dense blood serum and collect at the bottom of the container. Suppose the centripetal acceleration of the sample is 3.77 x 103 times as large as the acceleration due to gravity. How many revolutions per minute is the sample making, if it is located at a radius of 6.85 cm from the axis of rotation?
Explanation / Answer
acceleration due to gravity = 9.81 m/s^2
centripetal acceleration = 3.77x10^3 * 9.81 m/s^2 ........................eq1
centripetal acceleration = v^2 / r, (where r is given =0 .0685m) .............eq2
by eq 1 & 2
v^2 / 0.0685 = 3.77x10^3 * 9.81
v = sqrt(0.0685 * 3.77x10^3 * 9.81)
v=50.33 m/s
v is the object tangential speed.
V = w*r
tangential velocity = angular velocity*radius
w=V/r= 50.55/0.0685= 737.95 rad/s
no. of rotation =w/[60*(2*pi)]
=737.95/[60*(2*3.14)]
=737.95/376.8
=1.95 Rpm