how do you calculate if a block of wood dropped form a tall building has attained a velocity of of 78.4 m/s, how long has it been falling?

Answer 1

I don't understand the question.

Answer 2

if gravity is rounded to 10 and 78.4 is rounded to 78:

-then, time= velocity/gravity

time=78/10
time=7.8

or...
time=78.4/9.8
time= 8