SOLUTION: Hi, I'm doing my Junior Cert next year and I have been practising sample papers but I don't know how to do this question! :( Plese Help! :) Deirdre constructs a “polytunnel” on

Algebra ->  Volume -> SOLUTION: Hi, I'm doing my Junior Cert next year and I have been practising sample papers but I don't know how to do this question! :( Plese Help! :) Deirdre constructs a “polytunnel” on       Log On


   



Question 760882: Hi, I'm doing my Junior Cert next year and I have been practising sample papers but I don't know how to do this question! :( Plese Help! :)
Deirdre constructs a “polytunnel” on a level part of her back
garden. Five vertical, semicircular metal hoops, each of
radius 2 m are attached to brackets at ground level and
covered with a polythene sheet. The hoops are 2 m apart.
Find the volume of air in the tunnel.

Thanks in advance! :)
-Lauryn

Answer by Cromlix(4381) About Me  (Show Source):
You can put this solution on YOUR website!
Hi Lauryn,
If you just consider your polytunnel as a whole cylinder, work out the volume for the whole cylinder and then halve it.
Length of polytunnel = 8m (4 x 2m)
Volume = Pi r^2 h (Using length instead of height)
= Pi* 2^2 * 8m
= 100.53m^3
Halve it
= 50.3m^3 (1 decimal place).
Hope this helps.
:-)