Answer:
D. protruding steel rebars .. #answerwithquality #BAL
Answer:
Explanation:
We know that Drag force![F_D](https://tex.z-dn.net/?f=F_D)
![F_D=\dfrac{1}{2}C_D\rho AV^2](https://tex.z-dn.net/?f=F_D%3D%5Cdfrac%7B1%7D%7B2%7DC_D%5Crho%20AV%5E2)
Where
is the drag force constant.
A is the projected area.
V is the velocity.
ρ is the density of fluid.
Form the above expression of drag force we can say that drag force depends on the area .So We should need to take care of correct are before finding drag force on body.
Example:
When we place our hand out of the window in a moving car ,we feel a force in the opposite direction and feel like some one trying to pull our hand .This pulling force is nothing but it is drag force.