A) How fast was the brick moving after 4s? Vf=? Vi=0 (because it was dropped, not thrown) A= -9.8m/s^2 (gravity) t= 4s Use the equation Vf=Vi+A(t) Vf=0+(-9.8)(4) Final answer: Vf= -39.2m/s b) How far did the brick fall after 4s? D=? Vi=0 t=4s A=-9.8m/s2 **You do have the final velocity, but it is best to avoid using numbers that you have calculated yourself.** Use the equation: d=Vi(t)+0.5(A)(t)^2 d=(0)(4)+0.5(-9.8)(4)^2 d=(-4.9)(16) d=-78.4m Therefore, after 4s the brick fell 78.4m
