This entry was posted on Thursday, March 4th, 2010 at 10:02 am and is filed under Tile roofing. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.
A roofing tile falls from rest off the roof of a building.?
A roofing tile falls from rest off the roof of a building. An observer from across the street notices that it takes 0.37 s for the tile to pass between two windowsills that are 2.2 m apart. How far is the sill of the upper window from the roof of the building?
2.2/0.37 = average speed = 5.946 m/s
velocity at top sill = 5.946 – ((0.37/2) x 9.8) = 4.133 m/s
v = at
4.133/9.8 = t = 0.42173 secs
since the tile fell from rest
s = 1/2gt^2
4.9 x 0.42173^2 = 0.8715 m (answer)
may i Know the exact location of nice metal a factory of tile span for roofing in Tanza Cavite?
2 Responses to “A roofing tile falls from rest off the roof of a building.?”
Leave a Reply
March 4th, 2010 at 3:17 pm
The distance the tile falls in a given time "t" is:
d = ½gt²
Apply this to the the upper windowsill: call its distance (from the roof) "d1", and the time "t1":
d1 = ½g(t1)²
Apply it to lower windowsill ("d2" and "t2"):
d2 = ½g(t2)²
> "…windowsills that are 2.2 m apart…"
This means:
d2 – d1 = 2.2m
or:
½g(t2)² – ½g(t1)² = 2.2m
or, simplified:
½g((t2)² – (t1)²) = 2.2m
> "…takes 0.37 s "
This means:
t2 – t1 = 0.37 s
The rest is algebra. Solve these simultaneous equations to get t1 and t2:
½g((t2)² – (t1)²) = 2.2m
t2 – t1 = 0.37 s
Then, use "d1 = ½g(t1)²" to get d1
References :
March 4th, 2010 at 4:06 pm
2.2/0.37 = average speed = 5.946 m/s
velocity at top sill = 5.946 – ((0.37/2) x 9.8) = 4.133 m/s
v = at
4.133/9.8 = t = 0.42173 secs
since the tile fell from rest
s = 1/2gt^2
4.9 x 0.42173^2 = 0.8715 m (answer)
References :