Question

A plane lands and comes to a complete stop through 180 m of runway with a deceleration of 6.25 m/s2 [N]. Determine the plane’s velocity when it first touched the landing strip.

Answer 1

Answer:

47.43 m/s

Explanation:

Given that,

Final speed of a plane, v = 0

Distance, d = 180 m

Acceleration of the plane, a = -6.25 m/s² (deceleration )

We need to find the plane's velocity. Let it was u. So, using the third equation of kinematics as :

$v^2-u^2=2ad\\\\u^2=0^2-2\times (-6.25)\times 180\\\\u=\sqrt{2250} \\\\u=15\sqrt{10}\ m/s\\ \\\text{or}\\\\u=47.43\ m/s$

So, the plane's velocity when it first touched the landing strip is 47.43 m/s.