Posted by **Lori** on Tuesday, October 16, 2012 at 5:31pm.

An airplane is cruising at 340 km/h at an altitude of 4000 m. If the plane passes directly over an observer on the ground, how fast is the distance from the plane to the observer changing when it is 3000 m away from the point directly above the observer?

- calculus -
**Steve**, Tuesday, October 16, 2012 at 6:11pm
if the distance from the plane to the observer is y, and the distance the plane has flown is x, all in km,

y^2 = 4^2 + x^2

2y dy/dt = 2x dx/dt

when x = 3, y=5

10 dy/dt = 2(3)(340)

dy/dt = 204 km/hr

## Answer this Question

## Related Questions

- Calculus - At a given moment, a plane passes directly above a radar station at ...
- Calculus - Derivatives - chain rule An airplane, flying horizontally at an ...
- Calculus - Derivatives - chain rule An airplane, flying horizontally at an ...
- Physics - A supersonic jet travels at 3.0 Mach (i.e. at three times the speed of...
- Calculus - A plane flying with a constant speed of 14 km/min passes over a ...
- Calculus Help - A plane flies horizontally at an altitude of 6 km and passes ...
- A plane flies horizontally at an altitude of 5 km - A plane flies horizontally ...
- Calculus some1 plz!!!! - A plane flies horizontally at an altitude of 5 km and ...
- calculus - shortly after taking off, a plane is climbing at an angle of 30° and ...
- precalculus - A model airplane 50 feet above the ground is flying away from an ...

More Related Questions