An aeroplane makes in emergency landing without landing gear. If the aeroplane touches down with a horizontal speed of 60.0ms^-1 and the coefficient of friction for aluminium on asphalt is μ = 0.500, how far will the aeroplane slide before coming to rest? You may assume that acceleration due to gravity is 10.0ms^-2 and that air resistance is negligible.
average speed = 30
time to stop = t = d/30
-mu m g = m a
a = -10 mu = - 5 m/s^2
v = 60 + a T
0 = 60 -5 t
t = 12 seconds to stop
then
d = 60 (12) - (1/2)(5)(144)
d = 5 (144) - 2.5(144)
d = 2.5 * 144