The Experiment
This experiment will show how much rainwater that will be left in
the streets and in the fields, if the rain was not able to run
into the sewer or trickle into the ground. In this experiment
you will see how many mm of rainwater that would be left if it
is not able to run away.
Apparatus
• A container in which you
can collect the rainwater
• A scale
1.Measure the area of the container opening in mm²
|
How to do it |
Example |
Result |
|
Measure
the diameter (mm from side to side) of the opening |
100 mm |
100 mm |
|
Multiply
the diameter with the
diameter |
100 mm
multiplied with 100 mm |
10 000 mm² |
|
Multiply
this result with 3.14 |
10 000
mm²
multiplied with 3.14 |
31 400 mm² |
|
Divide the
result with 4 |
31 400 mm²
divided with 4 |
7 850 mm² |
Now you
have the area of the opening. You’ll use this result once the
rainwater is collected.
2. Collect the rainwater
Place the
container outdoors and let it stand there for 24 hours (for
example from 7 am to 7 am)
Bring the
water you have collected to school and pour it in the class
bucket.
3. Measure the volume of the rainwater
Now you
will have to calculate the volume of the rainwater the whole class
have collected. This is how you do it.
|
This is how you do it |
Example |
Result |
|
Weigh the
water that the entire class have collected |
250 g |
250 g |
|
Multiply
the weight with 1 000 mm³/g |
250 g
multiplied by 1 000 mm³/g |
250 000
mm³ |
4. Calculate how much rain has fallen
Now you
will find out how high the rain would have stood if it had stayed
on the ground. This you do by dividing the volume of entire class
collected rainwater with the sum of all areas of the container
openings.
|
This is how you do it |
Example |
Result |
|
Divide the
volume of all the area
of the
container openings |
25 000 mm³
divided with
7 800 mm² |
3.205 mm |
This means that the amount of rainwater is 3.205 mm
Take this measurement and fill in on the website
http://www.tgcproject.org |
