Posted by John on Thursday, September 22, 2011 at 4:47pm.
An airplane needs at least 145 meters of runway to take off. If the plane starts from rest and accelerates uniformly to a takeoff speed of 170 km/hr then what is its acceleration in meters/second? How long does it take for the plane to become airborne?

physics  Steve, Friday, September 23, 2011 at 10:41am
First, get everything in the same units. The answer must be in m/sec^2, so we need to convert 170 km/hr to m/sec.
170 km/hr * 1000m/km * hr/3600sec = 47.222m/sec
Now, we know that it takes some time, t, to take off.
v = at
47.222 = at, so
t = 47.222/a
Distance s = 1/2 at^2
145 = 1/2 a (47.222/a)^2 = 2229.938/2a
290a = 2229.938
a = 7.69 m/sec^2
So, checking our answer
t = 47.222/7.69 = 6.14 sec
s = 1/2 * 7.69 * 6.14^2 = 144.955 m
Close enough for jazz.
Answer This Question
Related Questions
 Physics  A jet plane has a takeoff speed of Vto=125km/h (34.72 m/s) and it's ...
 Science  The airplane can take off when its airspeed (speed of the air flowing ...
 physics  An airplane requires 420 m of runway to take off from an airstrip. If ...
 Physics  An airplane requires 420 m of runway to take off from an airstrip. If ...
 physics  the takeoff speed for a large airplane is 180 mi/hr(roughly 80m/s0 the...
 physics  To take off from the ground, an airplane must reach a sufficiently ...
 physics  the required takeoff speed for a large airplane is 180mi/hr(80m/s)the ...
 Physics  An airplane must reach a speed of 240.5 mi/h in order to take off. If ...
 phys  An airplane must reach a speed of 185 mi/h to take off. If the runway is...
 physics  A plane accelerates from rest at a constant rate of 5.00 m/s2 along a ...
More Related Questions