$($a$)$ Wind at $\backslash (20^\{\backslash$circ$\}\backslash$mathrm$\{$C$\}\backslash )$ is blowing with a velocity of $\backslash (20\backslash$mathrm$\{$~m$\}/\backslash$mathrm$\{$s$\}\backslash )$ on a drum shown in Figure $1.$ Determine the minimum drum weight needed to prevent the drum from tipping over. The diameter of the drum is $60$ cm $,$ and the height is $100$ cm $.$

$($b$)$ An airplane with a wing loading $($aircraft weight divided by the wing area$)$ of $\backslash (2000\backslash$mathrm$\{$~N$\}/\backslash$mathrm$\{$m$\}^\{2\}\backslash )$ has the aerodynamic characteristics given in Figure $2.$ Under cruise conditions, the lift coefficient is $0\mathrm{.}4.$ If the wing area is $\backslash (10\backslash$mathrm$\{$~m$\}^\{2\}\backslash ),$ find the drag force.

$($c$)$ The aerodynamic drag on a car depends on the "shape" of the car. A car has a drag coefficient of $0\mathrm{.}36$ when the windows and roof are closed. With the windows and roof open, the drag coefficient increases to $0\mathrm{.}45.$ Determine the car speed required to overcome the aerodynamic drag when the windows and roof are open to maintain the same amount of power as it is when the car is travelling at $\backslash (105\backslash$mathrm$\{$~km$\}/\backslash$mathrm$\{$hr$\}\backslash )$ with windows and roof closed. Assume the projected area remains the same.