This experiment allows you to investigate how the time period of a mass-spring system varies under different tensions. Weights can be added to the end of the spring and the motion timed. The spring constant for the spring can be determined. This is one of thirty experiments from the Virtual Physics Laboratory. This has gained the Association for Science Education's Green Tick of approval. More information at https://www.virtual-science.co.uk/ This is a free Physics resource which you are free to use in the classroom. If you need more comprehensive instructions then email me for them at rob@virtual-science.co.uk.