time to get to 8th floor:
t = v/g
distance fallen during that time:
y = 1/2gt^2
divide by 8m/floor
and yes it fell 15 floors total (watch, the last is 12m)
a worker on the roof of a building that is under construction dropped a 0.125 kg wrench over the edge. another workman on the 8th floor saw the wrench go by and determined that its speed at that level was 33.1 m/s. the first floor of the building is 12.0m high and each successive floor is 8.00m high. neglecting air friction, how many floors does the building have? how fast was the wrench falling just before it hit the ground? what was its kinetic energy just before it hit the ground?
Update: Other question, how do you know this 7 + 8 = 15 floors the 8 value, is it because it fell another eight floors to reach the bottom?
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