A roofer drops a nail that hits the ground traveling at 26 m/s. How fast was the nail traveling 1 second before it hits the ground?

vf = vi + at

vf - vi = at

vi = 0, vf=26 and afor nil = 9.8m/s2

26 = 9.8t

t = 26 / 9.8 = 2.65 s

Now we know the total time, so we can calculate the time 1 second before it hit the ground.

= 2.65 - 1 = 1.65s

Now again using the same equation, vf = vi+at, we can find vf

vi = 0, a = 9.8 t=1.65

vf = 0 + 9.8 (1.65) = 16.17 m/s

So, the nail is traveling with the speed of 16.17m/s 1 second before it hits the ground.