6 Procedure for stretching a spring
1. Place a heavy weight on the clamp stand to stop it falling over
2. Attach metre ruler and spring
3. Read position of pointer on ruler, this is the un stretched length of the spring
4. Hang 1N weight on the spring, read new position of pointer of the ruler
5. Continue adding 1N weights to the spring and reading position of the pointer
6. Calculate extension using ruler: subtract length of un stretched spring from each reading
7. Plot graph of extension vs weight
