Controlled Variables

Controlled variables in my experiment were as follows:
.time each shape of material held on to the weight (10s)
.the size of each shape of material (25 square centimetres)
.where the material was held (by the edges)
.the quality of the material before experiment (no rips
.the plastic bag used to hold each weight (same bag with weight of 6g).
.the dimensions for each shape were kept the same (12.5cm X 2cm rectange)
.the impact of the sudden weight on them (gently lifted from carpet after starting
stopwatch)

Risk assessment

This shows some ways to minimise the risk of investigating the strengths of different materials and shapes.

Raw results

Let W be the strength the material and shape can hold.
6g is added to every weight because that is the weight of the plastic bag which is holding the weights, and lifted by the materials.
You need to click on the image and then enlarge it to see the results.

Material strength experiment done and repeated

I conducted the experiment recording 3 sets of results during the long weekend.
Aim: To find how much weight each material and shape will hold.
Hypothesis: As the weight increases, the square paper will take the longest to break.
Equipment:
Ktichen scale
100g weight
200g weight
500g weight
1kg weight
Materials:
2 Plastic bags
Roll of aluminium foil
Roll of cling wrap
Paper
Method:
1) Cut the plastic bag, cling wrap, aluminium foil and paper into three shapes each; square, rectangle and circle.
2) Weighed the plastic bag where the weights would be put on.
3) Held up the plastic bag with each material of each shape for 10 seconds.
4) If it didn't break, then repeated step 3 with 100g weight and if broken, then recorded down the weight it can hold and the weight at which it broke.
5) Repeated steps 3-4 with 200g, 300g (100g+200g), 500g, 600g(100g+500g), 700g(500g+200g), 800g(500g+300g), 1kg, 1.1kg(1kg+100g), 1.2kg(1kg+200g), 1.3kg(1kg+300g), 1.5kg(1kg+500g), 1.6kg(1kg+500h+100g), 1.7(1kg+500g+200g)kg and 1.8kg(1kg+500g+200g+100g) weights.
6) Repeated steps 3 to 5 with all the different materials and their shapes.