Question

B2. (a) Write the balance of the forces acting on a 2 mm spherical particle, which is denser than the Newtonian liquid surrounding it. Derive an expression describing its terminal velocity [51 The drag coefficient of a sphere is given by: 24 C = Re Re, <2 18.5 CP Re 2Re, 500 Re 500 C 0.44 (b) Use the above drag coefficients and the expression obtained in (a) to compute the teminal velocity of a 2 mm glass bead (= 2500 kgm) in glycerol (p 1400 kgm 14 Pa [5] (e) Discuss briefly whether it is possible to avoid any sedimentation by using a liquid with different heological behaviour. 12] (d) In what characteristies does a non-colloidal partiele differ from a colloidal particle? Describe the behaviour of both colloidal and non-colloidal particles with respect to sedimentation [5

Answer 1

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