Question

A slingshot consists of a light leather cup attached between two rubber bands. It takes a force of 33 N to stretch the bands 1.3 cm.
A) what is the equivalent spring constant of the rubber bands? Answer in n/m
B) how much force is required to pull the cup of the slingshot 4.2 cm from its equilibrium position? Answer in units of N

Answer 1

Use same procedure as
http://www.jiskha.com/display.cgi?id=1329443884
but note that the numbers are different.