Kinematics physics determine the time

Question

An airplane is recovered aboard an aircraft carrier with a steel cable that brings airplane from 69 m/s to the ship speed of 15.0 m/s over displacement of 81 m determine the time, in seconds, that it takes to arrest (bring to rest) the aircraft

Answer 1

Using Lee H.'s idea of doing this relative to the aircraft, we still have the same knowns as last time:

 

v_o = 69-15 = 54 m/s  (initial velocity of aircraft relative to ship)

v = 0 (aircraft ends at rest with respect to ship)

(x-x_o) = 81 m (with respect to ship)

 

And we want to solve for time t.

 

So we can use:

 

(x-x_o) = (1/2)(v + v_o)t

 

81 m = (1/2)(0+54 m/s)(t)

81 = 27t

 

t = 3 s

 

Hope this helps!  Let me know if you have any questions about the technique or assumptions.