Tutorial Chp2 (Additional Question)

1. If the density of a liquid is 835kg/m3, find its specific weight and specific gravity.(ans: 8.20kN/m3, 0.837)

2. At what pressure will air at 490C weight 18.7 N/m3. (ans: 176kPa)

3. Determine the absolute viscosity of mercury in Ns/m2 if the viscosity in poises is 0.0158. (ans: 1.58x10-3 Ns/m2)

4. Refer to fig 1. A fluid has absolute viscosity 0.0010 lb-sec/ft2 and specific gravity 0.913. Calculate the velocity gradient and the intensity of shear stress at the boundary and at points 1in, 2in and 3in from the boundary, assuming (a) a straight line velocity gradient distribution and (b) a parabolic velocity gradient distribution. The parabola in the sketch has its vertex at A. Origin is at B. Given the velocity equation is V=45-5(3-y)2.

Figure 1

5. What is the smallest diameter glass tube that will keep the capillary height-change of water at 200C less than 0.9mm? (ans: 33.1 mm)

3”

y

45 in/sec

A

B

V

V