Question

7. An aeroplane heads due north at 500 km/h. It experiences a 80 km/h crosswind flowing in

the direction N60oE.

(a) Find the true velocity of the aeroplane. (7)

(b) Determine the speed of the aeroplane. (Leave your answer in terms of square root

Answer 1

$a^2=b^2+c^2-2bc cos \alpha$

$a^2=500^2+80^2-2(500)80cos(60°)=250000+6400-40000=216400$

true velocity of the aeroplane =speed of the aeroplane

$a=\sqrt{216400}$