Hooker's law. The distance d when a spring is stretched by a hanging object varies directly as the weight w of the object. If the distance is 39cm when the weight is 3kg, what is the distance when the weight is 9kg?

Question

Thank you, before hand.

Answer 1

39/3 = 13 cm/kg, the spring "rate" of the spring.

Therefore, the d for 9kg is

d = 13cm/kg x 9kg = 117cm.