Battle Of The Threads (Funky Physics Experiments)

You will need:

1. Cotton thread
2. Small bottle of water or
   any drink (filled)
3. Scissors

Understand the laws of shock loading by carrying out a simple project with your household items. Do be careful not to hurt yourself though.

INSTRUCTIONS

1. Cut out 2-3 large pieces of thread
   (about 40 cm in length).
2. Tie one end each of both threads to the bottle tightly so that it may not come loose.
3. Take one of the threads that you tied to the bottle and tie it to a stationary solid object so that the bottle may be left hanging by a thread.
4. Next, take the other thread that has been tied to the neck of the bottle and pull the thread very slowly until the thread breaks.
5. Using another thread, re-tie the bottle to a solid object with the thread, in the same way as before.
6. This time, pull the loose thread very quickly. Which thread breaks?

RESULT

When the thread is pulled slowly, the tension in the upper thread (which is greater than the second thread since it is supporting the weight of the bottle) causes the thread above the bottle to snap. When you pull the second thread very fast, the thread which you are pulling breaks. This is because the second thread is pulled quickly, creating enough force to snap it without increasing the tension in the above thread.