a 52g. weight tied to a spring stretches the spring 1.3cm. How many grams would it take to stretch the spring 3cm?
Assuming the amount of stretch is proportional to the weight, ...
52/1.3 = x/3
x = 3(52/1.3) = 120 g
52/1.3 = x/3
x = 3(52/1.3) = 120 g