At position A within a tube containing fluid that is moving with ...

[joblessjake]

At position A within a tube containing fluid that is moving with steady laminar flow, the speed of the fluid is 12.0 m/s and the tube has a diameter 12.00 cm.
 
  At position B, the speed of the fluid is 18.0 m/s and the tube has a diameter 6.00 cm. What is the ratio of the density of the fluid at position A to the density of the fluid at position B?
  A)
 
  3.00
 
  B)
 
  0.167
 
  C)
 
  0.375
 
  D)
 
  0.333
 
  E)
 
  0.750

Question 2

A camera lens has a focal length of 50.0 mm and an aperture setting of f/4.00. What is the aperture diameter of this lens?
 
  A) 14.2 mm B) 13.6 mm C) 10.1 mm D) 12.5 mm E) 15.0 mm

[reversalruiz]

Answer to Question 1

C

Answer to Question 2

D