Question

The linear velocity of a point on the surface of earth at a latitude of $60^{\circ }$ is

• A. $\frac{800}{3}m{s}^{-1}$
• B. $\frac{800\pi }{3}m{s}^{-1}$
• C. $800\times \frac{5}{18}m{s}^{-1}$
• D. $\frac{2000\pi }{27}m{s}^{-1}$

Answer 1

Answer: (D)

$V=r\omega$
$r=Rcos\theta$
Where $R=6400km$ is radius of the earth; $\theta =60^{\circ }$ is the latitude angle.
$\omega =\frac{2\pi }{T}$ $(T=24hours=24\cdot 60\cdot 60s)$
$\therefore V=Rcos\theta \frac{2\pi }{T}=6400\times 10^3\times \frac{1}{2}\times \frac{2\pi }{24\cdot 60\cdot 60}=\frac{2000\pi }{27}m{s}^{-1}$