Question

What is the magnitude of the orbital velocity of the planet mercury (orbit radius =5.79× 10 7 km , orbital period = 88.0 days)?

Answer 1

The orbital speed of the planet mercury can be calculated by the formula,

$v=\frac{2\pi R}{T}$

Here, R is the orbital radius and T is the orbital time.

Given $R=5.79\times10^{7} km$ and $T =88 days$ (in second $T= 88 \times 24 \times 60\times 60=88\times86400 s$

Substituting these values in above formula we get,

$v=2\times\frac{22}{7} \times\frac{5.79\times10^{7} }{88\times86400}$

$v=47.89 km/s\simeq 47.9 km/s$

Thus, the orbital velocity of the planet mercury is 47.9 km/s