

Falling Airplane
Name: Erika
Status: student
Age: 17
Location: N/A
Country: N/A
Date: 1999
Question:
I need to know what's the average speed of an
airplane while moving in air? And if its falling would it be falling at
the gravitational velocity of 98m/s?
Replies:
Hello,
A commercial airplane travels at a velocity of about 600 miles per
hours. This is just under 1000 km/hrs, or 16 km/min, or about 270 m/second.
Some airplanes travel much slower and some much faster.
9.8 m/secondsquared is actually gravitational acceleration. It is the rate
of change of VELOCITY, not velocity itself.
When an object falls freely under the force of gravity, its velocity
increases until it reaches an equilibrium value, known as the terminal
velocity. At this velocity, the gravitational force (mass x acceleration)
exerted on the body is exactly balanced by a drag force due to air
resistance. This velocity remains almost constant to the end.
I do not know what the terminal velocity of an airplane is. I suppose it
very much depends on the size and the shape of the aircraft. But I know
that a person falling or parachuting out of an airplane (with the
parachutes closed) has a free fall velocity of about 120 miles per hr or
about 50 m/second.
I hope this helps.
Dr. Ali Khounsary
Advanced Photon Source
Argonne National Laboratory
Argonne, IL 60439
Cruising speeds for large commercial airplanes are always less than the
speed of sound. The speed of sound varies depending on atmospheric
conditions, but let us assume it is 1000 ft/sec which would then convert
to 681 miles per hour. Maximum cruising speeds are a bit lower but the
average duration of a flight from Frankfort, Germany to Chicago is
around 9 hours (we are heading into the wind) the trip is around 4000
miles, hence the average speed for the entire voyage is 444 miles per
hour.
I don't know what you mean by 98 meter/sec. The acceleration due to
gravity is 9.8 m/sec/sec.
A free falling object could have a considerably higher velocity
depending on its shape.
H. Myron
Erika  This is kind of like asking the aveage speed of a car. It varies a
lot depending on the car and the situation. Just a few thoughts:
Typical landing speed
Small general aviation aircraft (e.g. Cessna)
60 knots
Airliner 130 knots
Typical cruising speed
Small general aviation aircraft (e.g. Cessna)
120 knots
Airliner 500 knots
The Concord cruises at about 1400 knots and the Wright Brothers flew 120
feet in 12 seconds  10 feet per second
And if its falling would it be falling at the
gravitational velocity of 9.8m/s?
In free fall  without considering air resistance  it would fall at 9.8
m/s. In a power dive it could be much faster than this. Hope this helps.
Larry Krengel
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Update: June 2012

