Air at 37.8 °c and 101.3 kpa absolute pressure flows at a velocity of 23 m/s past a sphere having a diameter of 42 mm. what are the drag coefficient and the force on the sphere?

Explanation:

The given data is as follows.

  T = ,   ,  r = kg/ms

  Diameter (D) = 42 mm = = 0.042 m

  Velocity, = 23 m/s

Formula for Reynold number is as follows.

Putting the given values into the above equation as follows.

                               =

                               =  

As it is known that drag coefficient for sphere is equals 0.47.

Hence, formula for total drag force is as follows.

              ......... (1)

                  =  ....... (2)

Putting equation (2) in equation (1) as follows.

or,          

                               =                

                               = 0.1958 N

Thus, we can conclude that the force on the sphere is 0.1958 N.

the answer is c i believe