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