The purpose of this experiment is to design 2 independent experiments that can be conducted to determine the spring constant of the spring within a pen.

Question

Materials

·     Clicking Pen

·     Meter Stick

·     Stopwatch

·     Phone camera (slow motion)

·     Any thing else that would help you make the necessary measurements

1)    Design an experiment which you can conduct at home to determine the spring constant of the spring in a clicking pen. Describe what you will do. You do not need to include equations here.

2)    Come up with a mathematical procedure which you can use to determine the spring constant of the spring. Rearrange the equation to get the spring constant, k, on its own.

3)    Design a second independent method that would allow you to determine the spring constant of the spring. This can be as simple as you would like it to be.

Answer 1

Hi Britney C.

Your two types of experiments are: static load (spring stretches for a known force, you measure); and dynamic (put masses on each end of the spring, on a low-friction surface, and let them wiggle in a resonant cycle). Note that the latter measurement method can determine both the compression k and the bending k for the spring. Should those k's be equal? What would "equal" be in units, given that the restoring force for bending is proportional to angle of deflection, rather than a distance per se.

-- Cheers, -- Mr. d.