A 1:10 scale model of a tractor-trailer rig is tested in a wind tunnel. The model frontal area is Am = 0.1 m2 . When tested at Vm = 75 m/s in standard air, the measured drag force is FD = 350 N. Evaluate the drag coefficient for the model conditions given. Assuming that the drag coefficient is the same for model and prototype, calculate the drag force on a prototype rig at a high-way speed of 90 km/h. Determine the air speed at which a model should be tested to ensure dynamically similar results if the prototype speed is 90 km/h. Is this air speed practical? Why or why not?

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the equation above shows how temperature f, measured in degrees fahrenheit, relates to a temperature c, measured in degrees celsius. based on the equation, which of the following must be true?

a temperature increase of 1 degree fahrenheit is equivalent to a temperature increase of

5

9

degree celsius.

a temperature increase of 1 degree celsius is equivalent to a temperature increase of 1.8 degrees fahrenheit.

a temperature increase of

5

9

degree fahrenheit is equivalent to a temperature increase of 1 degree celsius.

a) i only

b) ii only

c) iii only

d) i and ii only

answer:

on fri feb the green land, the only one who can