An object is dropped from a height of 100m, How long is it in the air?

Initial velocity Vi=0 m/sHeight = h = 100mand g=9.8m/s^2time=T=? using second equation of motion ... h=ViT + (gT^2) / 2h = (0) (T) + (9.8/2) T^2h = 4.9 T^2100=4.9 T^2T^2=100/4.9T^2 = 20.41T = sqrt (20.41) T = 4.52 sec