A sample of blood is placed into a centrifuge of radius 15.0 cm. The mass of a red corpuscle is 3.0 10-16 kg, and the centripetal force required to make it settle out of the plasma is 4.0 10-11 N. At how many revolutions per second should the centrifuge be operated?
Question 2
A box is dropped onto a conveyor belt moving at 2 m/s. If the coefficient of friction between the box and the belt is 0.3, how long before the box moves without slipping?