Question

How would you calculate the speed at which the earth revolves around the sun in m/s?

Answer 1

Step 1: Calculate the distance,

The average distance of the Earth from the Sun $r=1.5\times {10}^{11}m$

Hence, the circumference of the earth's orbit,

$D=2\mathrm{\pi r}$

$=2\times \mathrm{\pi }\times 1.5\times {10}^{11}$

$\approx 9.4\times {10}^{11}m$

Step 2: Calculate the total time,

Earth takes a whole year to complete the revolution over this orbit.

We know that $1yr=365$ days

$1$ day $=24hrs$

$1hr=60mins$

$1min=60s$

Therefore, the total time taken is given as,

$t=365\times 24\times 60\times 60$

$\approx 3.15\times {10}^{7}s$

Step 3: Calculate the speed,

$\therefore$The tangential speed of the Earth,

$\frac{9.4\times {10}^{11}}{3.15\times {10}^7}\approx 3\times {10}^{4}m{s}^{-1}$

Hence, the earth revolves around the sun at a speed of $3\times {10}^{4}m{s}^{-1}$.