Question

A jet airliner moving initially at 889 mph

(with respect to the ground) to the east moves
into a region where the wind is blowing at
830 mph in a direction 59° north of east.
What is the new speed of the aircraft with
respect to the ground?
Answer in units of mph.

Answer 1

1500 mph

Step-by-step explanation:

Take east to be +x and north to be +y.

The x component of the velocity is:

vₓ = 889 cos 0° + 830 cos 59°

vₓ = 1316.5 mph

The y component of the velocity is:

vᵧ = 889 sin 0° + 830 sin 59°

vᵧ = 711.4 mph

The speed is found with Pythagorean theorem:

v² = vₓ² + vᵧ²

v² = (1316.5 mph)² + (711.4 mph)²

v = 1496 mph

Rounded to two significant figures, the jet's speed relative to the ground is 1500 mph.