3. In a microhematocrit centrifuge, small samples of blood are placed in capilla

Question

3. In a microhematocrit centrifuge, small samples of blood are placed in capillary tubes with heparin, an anticoagulant. The tubes are rotated at 11,500 rpm, with the bottom of the tube being 9.07cm from the axis of rotation. a) What is the linear speed of the bottom of the tubes? b) What is the centripetal acceleration at the bottom of the tubes? c) What angular speed must the centrifuge have if the centripetal acceleration at the bottom of the tubes is 10,000g, i.e. 10,000 times greater than the acceleration due to gravity on the Earths surface?

Explanation / Answer

a.

The linear speed is calculated as follows:

v = rw =[0.0907] [11500 rpm] = 0.0907*[1200 rad/s] = 109 m/s

b.

The centripetal acceleration is calculated as follows:

a = v^2/ r = 109*109 / 0.0907 = 131000 m/s^2

c.

The angular speed is,

w = sqrt [a / r] = sqrt [10000*9.81 / 0.0907] = 1040 rad/s = 9940 rpm

Related Questions

Navigate

• Browse (All)
• Browse 3
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.