Respuesta :

It takes 7.0s for a piece of wood to be falling from a tall building in the velocity of 68.6 m/s

Explanation:

v = u + at

68.6 ms^-1 = 0 ms^-1 + (9.8 ms^-2 x t)

t = 68.6 ms^-1 / 9.8 ms^-2

t = 7.0s

It takes 7.0s for a piece of wood to be falling from a tall building in the velocity of 68.6 m/s