Risk Assessment + Control Variables

Risks involved in the experiment include . . .

Identifying it:

- cutting one side of the aluminium foil container

- placing woodchips in the sand bag

- sewing the sandbags on the machine

Assessing it:

- Possibly attaining a cut from sawing off the side of the aluminium foil container

- Receiving splinters when placing woodchips in the sandbag

- Piercing a needle through your finger while sewing the sand bags

Controlling it:

- Be aware of where body parts (arms, fingers, legs etc.) are

- Gloves should be worn at all times when handling woodchips

- Have adult supervision when sewing and sawing

How the variables will be controlled

The variables (controlled variables):
o The size of the sandbag : each sand bag, when finished will measure 13.5cm x 7.0cm
o The amount of water poured through : a 1.25L bottle will used so that exactly 1.25L of water will be poured
o The way the sandbags are stacked : there will be three sandbags laid next to each other, with two levels, they should be stacked like bricks
o Shape of the aluminium container : only one aluminium foil container will be used so that the shape remains the same
o Size of the container : only one aluminium foil container will be used so that the size remains the same
o Amount of material placed in each sandbag : the material (sand, woodchips, coarse gravel etc) will be poured into the sandbag until there is 1cm left at the top for the sand bag to fold
o The shape of the sandbag : each sand bag will have a rectangular shape
o The time allowed for the water to run through : a timer will be used and the water will be allowed 5mins to run through before it is stopped
o The rate at which the water is being poured : the water will be poured by hand and care will be taken for it to be poured at a steady rate

Dependent variable:
o The amount of water that escapes past the sandbags.

Independent variable:
o The materials that are placed in the sandbag (sand, woodchip, coarse gravel and soil)