Question

1. A very tall skycraper sways back and forth every 4.0 seconds.

Period:

Frequency:

2. A pendulum takes 0.5 second to complete one cycle.

Period:

Frequency:

Answer 1

1) Period:

$$T=4.0\ s.$$

Frequency:

$$f=\dfrac{1}{T}=\dfrac{1}{4.0\ s}=0.25\ Hz.$$

2) Period:

$$T=0.5\ s.$$

Frequency:

$$f=\dfrac{1}{T}=\dfrac{1}{0.5\ s}=2\ Hz.$$