Example $2\mathrm{.}2$ The Boeing $777($Fig$.1\mathrm{.}2)$ has a wing planform area of $4605$ square feet $(f{t}^2).($a$)$ Assuming a takeoff weight of $506,000lb$ and a takeoff velocity of $160m\frac{i}{h},$ calculate the lift coefficient at takeoff for standard sea$-$level conditions. $($b$)$ Compare the above result with the lift coefficient for cruise at Mach number $0\mathrm{.}83$ at $30,000ft,$ assuming the same weight.