Question

a slingshot consists of a lighter leather cup attached between two rubber bands. if it takes a of force of 32 N to stretch the bands 1.2cm, what is the equivalent spring constant of the two rubber bands?

Answer 1

From the Hook's law, the spring constant can be expressed as follows:

$$k = \dfrac{F}{x}$$

where $F = 32N$ is the elestic force (which is equal to the applied one if rubber bands do not move after stretching), and $x = 1.2cm = 0.012m$ is the elongation of the bands. Thus, obtain:

$$k = \dfrac{32N}{0.012m} \approx 2667N/m$$

Answer. 2667 N/m.