Spring Pendulum
Physics: Simple Harmonic, Pendulum ?

A 167 g ball is tied to a string. It is pulled to an angle of 6.8^circ and released to swing as a pendulum. A student with a stopwatch finds that 30 oscillations take 18 s.
How long is the string?

The 14-cm long wrench in the figure swings on its hook with a period of 0.89 s. When the wrench hangs from a spring of spring constant 330 N/m, it stretches the spring 3.1 cm.

What is the wrench’s moment of inertia about the hook?
IMAGE: http://session.masteringphysics.com/problemAsset/1070606/8/14.EX25.jpg

The weight of the ball and the angle of pull are irrelevant. The period is governed by the length of the string and the force of gravity, nothing else.

Spring Pendulum