# The acceleration of a descending airplane

## Homework Statement

An airplane descends in a circular pattern with a constant radius of 250 meters. The airplane has a horizontal speed of 75 m/s (constant) and a downward
speed of 5 m/s, which is increasing at a rate of 2 m/s2

Determine the acceleration of the airplane.

an = v2 / ρ

a = √(at2 + an2)

## The Attempt at a Solution

Finding the acceleration for a circular motion is easy, but I am having trouble including the downward acceleration. Any help is greatly appreciated!

#### Attachments

• 29.2 KB Views: 307

Related Introductory Physics Homework Help News on Phys.org
Ibix
If all else fails, derive it from first principles.

Assuming that the aircraft is at height h and is circling the origin, can you write down its position as a function of time? If so, what's its acceleration?

What equation could I use to include the height and downward speed as a function of time?

rcgldr
Homework Helper
Finding the acceleration for a circular motion is easy, but I am having trouble including the downward acceleration.
You figured out the centripetal accleration, and the problem states the downwards acceleration is 2 m / s2, which would be the components of the acceleration vector (horizontal and vertical). To get the magnitude, take the square root of the sum of the squares of the components.