Question

A simple pendulum that consist of a rock of mass 3.5 kg tied to the end of a (massless) string of

length 1.5 m.

(a) What is the frequency of the pendulum?

(b) What is the period of the pendulum?

Answer 1

a)

$$f=\frac{1}{2\pi}\sqrt{\frac{g}{l}}\\f=\frac{1}{2\pi}\sqrt{\frac{9.8}{1.5}}=0.41\ Hz$$

b)

$$T=2\pi\sqrt{\frac{l}{g}}\\T=2\pi\sqrt{\frac{1.5}{9.8}}=2.5\ s$$