Math
posted by Molly on .
A man on the 8th floor of a building sees a bucket (dropped by a window washer) pass his window and notes that it hits the ground 1.5s later. Assuming a floor is 12ft high (and neglecting air friction), from which floor was the bucket dropped?

as it passed the window with speed s, it will fall
st+16t^2 feet in t more seconds
1.5s + 16*9/4 = 1.5s+36 feet
It fell 8*12 = 96 feet, so
1.5s+36=96
s = 40
since s = 32t, t = 1.25 at the 8th floor.
So, in the first 1.25 seconds, it fell
16*25/16 = 25 feet
Looks like it fell from the 10th floor.
Doesn't feel quite right. Better check my math.