Question

A planet is moving in a circular orbit. It completes $2$ revolutions in $360$ days. What is its angular frequency?

• A. $1.5\times 10^{-2}$ rad / day
• B. $2.5\times 10^{-2}$ rad / day
• C. $3.5\times 10^{-2}$ rad / day
• D. $4.5\times 10^{-2}$ rad / day

Answer 1

Answer: (C)

Planet completes $2$ rounds in $360$ days,
$\Rightarrow 2\times 2\pi$ rad in $360$ days
So, angular frequency $=\frac{\text{ angle }}{\text{ time }}=\frac{4\pi }{360}$
$=3.5\times 10^{-2}$ rad / day