1.The force of the wind blowing on a vertical surface varies jointly as the area of the surface and the square of the velocity. If a wind blowing at 50 mph exerts a force of 75 pounds on a surface of 500 ft^2, how much force will a wind of 75 mph place on a surface of 10 ft^2?

Question

irishboy123 · Answer

we can start off with $$F = k A v^2$$
does that make sense?

incidentally this looks a lot  like Rayleigh's law for drag :-)

irishboy123 · Answer

$$F_D\, =\, \tfrac12\, \rho\, u^2\, C_D\, A$$ i.e. $F\, =k \, v^2\,\, A \qquad \qquad$ ;-)) based on: https://en.wikipedia.org/wiki/Drag_equation

clamin · Answer

@IrishBoy123 what do i put for A and F??

irishboy123 · Answer

$$F\, =k \,   v^2\,\, A $$
$$v= 50 mph \quad F= 75 lbs, \quad A=  500 ft^2 \quad \text {solve for k}$$
$$v= 75 mph \quad k = \text{the same} \quad  A = 10 ft^2, \quad F = ???$$

irishboy123 · Answer

or $$\dfrac{F_1}{ v_1^2\,\, A_1} =k  = \dfrac{F_2}{ v_2^2\,\, A_2} $$

solve from there...

irishboy123 · Answer

and plug in some numbers to get a feel for it.