Hello, peon123!

A plane, flying at 2000 km/h, wishes to reach a city 3000 km due East,

encounters wind blowing from N70W with speed 100 km/h.

(a) Find the velocity of the plane relative to the ground.

(b) How long will it take to reach the city? Code:

D N
* :
*70°:
* :
oC
2000t * : * 100t
* : *
* 20°*
o - - - - - - - - - - - o
A 3000 B

The plane intends to fly from to : . km.

The wind is blowing from D to B: .

. . Hence: .

Because of the wind, the plane flies from A to C at 2000 km/hr.

. . In hours, it flies 2000t km: .

In the same hours, the wind blows from C to B: . km.

In , Law of Cosines: .

This simplifies to: .

Quadratic Formula: .

. . which has the positive root: .

(b) The flight took 1.433 hours.

(a) The plane's speed was: .