Spring Pendulum

• Spring pendulum
• The concept of potential energy
• The concept of kinetic energy

As we have seen from the experimental set up our spring pendulum consists of a mass hung from a massless spring; when a mass m is loaded the force of gravity together with the spring response cause the mass to oscillate around the equilibrium position towards which our system is naturally carried to relax under the effect of the air friction.

As a first step let us hang a mass m to our spring and record its position on the graduated scale once the equilibrium is reached; let us move it from this position elongating the spring by a length Δx and by means of the provided stop watch measure the time our pendulum takes to perform several oscillations around the equilibrium position.

What would we observe repeating the same step if we switched from m to 4m and then to 8m?

From the considerations, we can determine the value of the elastic constant of the spring dynamically.

So the net effect of gravity is just to shift the oscillation point without affecting the amplitude.

• Steel spring with pointer,dia. 21 x 140 length mm, wire diameter0.75 mm — 4110.81
• Digital chronometer — 2231.52

• Does the mass of the pendulum affect the oscillation period in the approximation of small oscillations?
• Consider a pendulum of length L. How many times should I reduce L of the pendulum to make the period T half of the initial value?