army private olivia dobbs observes a fighter plane known to be flying at a level elevation of 6.3 kilometers moving away from her. at one point she observes the plane at an angle of elevation of 49 degrees while one minute later the angle of elevation is 15 degrees. how fast is the plane flying in kilometers per hour?

333.55 km/hr

Explanation:

Elevation = 6.3km

Angle of elevation = 49°

Current position

Using Pythagoras rule :

Tan θ = opposite / Adjacent

Tan 49 = x / 6.3

1.1503684 * 6.3 = x

x = 7.2473209

x = 7. 25 km

Position x, after 1 minute;

Tan θ = opposite / Adjacent

Tan 15 = x / 6.3

0.2679491 * 6.3 = x

x = 1.6880799

x = 7. 25 km

Difference in distance per minute :

(7.2473209 - 1.6880799) = 5.559241 km

Hence, distance covered per hour = (5.559241 * 60) = 333.55446 km

Speed = distance / time

Speed = 333.55446 km / 1 hr

Speed = 333.55 km /hr