Question

The beam of light house makes one complete revolution every 20 seconds how many degrees is it rotate in five seconds

Answer 1

Every 5 seconds the beam rotates 90 degrees;

`90^(\circ)`

Step-by-step explanation:

Given that the beam of a lighthouse makes one complete revolution every 20 seconds.

one complete revolution is;

`360^{\circ^{}}`

The rate of rotation is;

`r=(360^(\circ))/(20)=18^(\circ)\text{ per second}`

The number of degrees it will rotate in 5 seconds is;

`\begin{gathered} x=5* r=5*18^(\circ)per\text{ second} \\ x=90^(\circ) \end{gathered}`

Therefore, every 5 seconds the beam rotates 90 degrees;

`90^(\circ)`