Assuming a constant flow, what will happen to a fluid if the ...

[dmcintosh]

Assuming a constant flow, what will happen to a fluid if the cross-sectional area of the tube in which its flows decrease?
 
  a. Its velocity will increase.
  b. Its velocity will decrease.
  c. Its density will decrease.
  d. Its viscosity will decrease.

Question 2

What temperature is necessary to liquefy O2 at 1 atm pressure?
 
  a. 118.8 C
  b. 181.1 F
  c. 463.3 F
  d. 183.0 C

[KKcool]

Answer to Question 1

ANS: B
Throughout the tube, the fluid flows at a constant rate of 5 L/min. At point A, with a cross-sectional area of 5.08 cm2, the velocity of the fluid is 16.4 cm/sec. At point B, the cross-sectional area of the tube decreases to 2.54 cm2, half its prior value. At this point, the ve-locity of the fluid doubles to 32.8 cm/sec.

Answer to Question 2

ANS: D
Liquid O2 is produced by separating it from a liquefied air mixture at a temperature below its boiling point (183 C or 297 F). After it is separated from air, the O2 must be maintained as a liquid by being stored in insulated containers below its boiling point. As long as the temperature does not exceed 183 C, the O2 will remain liquid at atmospheric pressure. If higher tempera-tures are needed, higher pressures must be used. If at any time the liquid O2 exceeds its critical temperature of 118.8 C, it will convert immediately to a gas.