Most all materials, if put under a certain stress, will change. In the case of the string in our kit, it will stretch in length, and the amount of stretch depends on the type of string, its length, the amount of stress, and its thickness.

Set up the stand as shown here. Measure the string without any weight other than the hook. You should

also measure the diameter of the string.

Then you place a large weight and measure the length of the string under this stress.

Given these measurements, you should be able to calculate the Young's Modulus that applies to this material.