Lab Report: Banana

InvestigationBy: Marium SaeedRawan Al.AnsariJoud Abu-Odeh

Aim of the Investigation• The aim of this investigation was to test

the strength of different organic food materials.

• In this experiment our group tested the strength of the fibres in banana skin.

• The banana skin contains cellulose and microfibrils laid down in a mesh, like in all

plant fibres to make it strong and to protect the inside of the banana.

Our PredictionWe predicted that the banana skin would only support up to 5N of force, we did not think that the skin of the banana would be

very strong we thought it only acted as protection for the inside of the banana

from the outside environment.

Method1. Cut 4 pieces of 2cm thick rings of

banana 2. Take out the inside of the banana3. Hook on to the upper clamp one of

the banana rings4. Hook on to the lower clamp the force

meter5. Use the meter’s hook to attach it to

the banana ring6. Lower the clamp slowly until the

banana ring snaps7. Meanwhile, watching the scale at eye

level8. Record how many Newtons took to

snap the ring9. Repeat experiment with the second

banana

Steps

Cut the banana rings Mark with an X Hook onto Newton meter

Pull Newton meter While measuring at eye level Record how much force needed for the banana ring

to snap

ResultsBanana A Banana B

1st try 8N 8N

2nd try 10N 9N

3rd try 9N 10N

4th try 12N 9N

Average: 9.75N 9N

Total Average: 9.375 N

Data HandlingResults

8

109

12

89

109

0

2

4

6

8

10

12

14

1st try 2nd try 3rd try 4th try

Tries

New

ton

s t

o S

nap

Banana A

Banana B

Conclusion Although we tested two different bananas, our

results were very similar for each one, showing that the fibres in the banana skin

were almost the same strength because they came from the same plant and had been

through the same environmental conditions and had similar genetic codes. However we

could also see that the strength of the banana skin of each fruit may vary, for example

banana A was slightly stronger than banana B, withstanding an average force of 9.75N, while

banana B only withstood 9N.

Analysis We predicted that the bananas we were testing would only withstand a maximum of

5N, however after conducting the experiment, we saw that it was quite strong, withstanding

a force of more than 9N. This is due to its strong structure which contains cellulose microfibrils. These fibres are stacked up against each other in different angles to

increase the weight the skin could handle by being able to compress in different directions due to the applied pressure. This proved that

the banana skin provided protection and strength to the fruit.

Evaluation Our experiment was quite accurate

as we tried to keep all the other factors affecting the results of the experiment the same.

We made all the pieces 2cm wide and made sure that the same person took the readings each time, at the same eye level to avoid errors in the results.

We also cut the banana skin in ring shapes to test the banana skin in the direction of the plant fibres, rather than against it (vertically).

There was one result which was higher than all the others, however finding an average made it less likely to affect the overall results of the experiment.

Χ The experiment could be improved if we measured the width of the rings more accurately and by repeating the experiment again.

Χ We could have also tested different fruits to have a wider range of the role in which fibres play in protecting the inner fruit.

Χ Although we tried applying the force as accurately and as similarly as possible each time by using two clamps; using a mechanical machine which applied and read the exact force each time would have been more accurate.