Question

A source is moving on a circle of radius 3 m with constant angular velocity w = 5 rad/s. If the observer is at a distance 5 m from the centre of circle, the time interval between maximum and minimum frequency received by the observer is –

• A. $\frac{\pi}{5}$
• B. $\frac{2}{5}\cos^{–1}\left( \frac{3}{4} \right)$
• C. $\frac{2}{5}\cos^{–1}\left( \frac{3}{5} \right)$
• D. $\frac{2}{5}\sin^{–1}\left( \frac{3}{5} \right)$

Answer 1

Answer: (C)

$\frac{2}{5}\cos^{–1}\left( \frac{3}{5} \right)$

Answer 2

2q = wL

t = $\frac { 2 } { 5 } \cos ^ { - 1 } \left( \frac { 3 } { 5 } \right)$