4.9

Question 1

What is tensile strength?

Answer 1

It is the resistance of a material breaking when under tension.

Question 2

How do you investigate the tensile strength?

Answer 2

1. Extract the fibres from the plant by soaking the plant cell and leave it until the tissue surrounding are rotting and soft.
2. Clamp fibres at both ends and apply mass to middle, such as a weights. Let them be very light or heavy weights depending on the fibre tested.
3. Note the mass required to snap the fibre.

Question 3

What should you conclude?

Answer 3

You should observe that different species of plants have different tensile strengths of their fibres.

Question 4

What is the independent variable?

Answer 4

The type of fibre.

Question 5

What is the dependent variable?

Answer 5

How much mass can be held (the tensile strength)

Question 6

What other variable should be controlled?

Answer 6

• The length of the fibre
• Part of plant which fibre is taken from
• Temperature and humidity
• Solution used to soak the plants and time soaked
• The way the mass is attached