Question

The earth's radius is 6400 km. It makes one rotation about its own axis in 24 hrs. The centripetal acceleration of a point on its equator is nearly:

• A. $340cm/s^2$
• B. $34cm/s^2$
• C. $3.4cm/s^2$
• D. $0.34cm/s^2$

Answer 1

Answer: (C)

$3.4cm/s^2$

Given radius of the earth is 6400 km
velocity of a point on the equator is
$v=\frac{2\pi R}{24}km/hr$ (since the point covers 1 full rotation in 24 hrs)

acceleration of the equator point is
$a=v^2/R$

$a={6400}^2\times \frac{4{\pi }^2}{6400\times 576}km/h{r}^2$
$a=3.4cm/s^2$