to test the strength of cotton,wool,silk and nylon fibres
Answers
To compare the tensile strength of different fibres of same thickness and same length.
Things Needed : Thread (30 Cm in length) of cotton, wool, silk and nylon, an iron stand with a clamp, a pan and marbles (of the same weight)
Method : Take a cotton thread of about 30 cm in length and tie its one end to the clamp, and leave other end suspended freely. At the free end of the cotton thread, suspend a pan, so that the weight can be placed on it. After that, Gently put marbles one by one in the pan till the cotton thread breaks. Now, record the total numbers of marble required to break the cotton thread. The total numbers of marbles required to break the cotton thread is measure of its tensile strength. Repeat the activities with threads of wool, silk and nylon. Record the total number of marbles required to break the thread in each case.
Observation : We will observe that nylon thread holds maximum number of marbles before it breaks, followed by silk, cotton and wool (least strong). The threads which hold the maximum number of marbles is the strongest.
Precaution : All threads should be of the same length and almost of the same thickness.
Conclusion : Tensile strength of Nylon (synthetic fibre) is more than that of the silk cotton and wool.