A 8 kg object falls from a displacement of 20 meters for 2 s. What is the change in velocity?
Using
vf2 = vi2 + 2ad
Where
vf = final velocity
vi = 0
a = (-9.8)m/s^2
d = 20m
So we have
02 = vf2 + 2(-9.8)(20)
vf2 = 392m2/s2 take the negative square root of both sides
vf = about -19.8m/s [ and this will be negative since the motion is downward]
