Following: The drag force (Fdrag) exterted by air on a moving car depends on a d
ID: 1860838 • Letter: F
Question
Following:
The drag force (Fdrag) exterted by air on a moving car depends on a dimensionless drag coefficient (Cdrog), the specific volume of air (Vair), the velocity of the car (Vcar), and the frontal area of the car (Afront). Based on unit considerations alone, obtain an equation for the drag force. Be sure to explicity demonstrate that the final units are correct. Explain, based on your equation, what happens to the drag force when each variable is changed in isolation, what happens to the drag force when each variable is changed in isolation. Indicate whether this predicted behaviour matches your intuition in each caseExplanation / Answer
unit of force=MLT^-2 ; C=dimentionless ;
specific volume=volume/mass=M^-1L^3 ;
Velocity=LT^-1 ;
Area=L^2 ;
Force is proportional to all these factors so ;
Specific volume has power of -1 ;
velocity has power of 2 so as dimention T gets equal and area is 1 ;
F=C*A*V^2/specific volume;
b) Inceasing C,velocity,area would increase drag force and increasig specific volume would decrease drag force