Question

If the radius of the Earth's orbit around the Sun is 150 million km, what is the speed of the Earth?

Answer 1

The gravitation force grant the centripetal force.

Explanation:

`F_g = F_c`
`F_g=(G M_(sun) M_(earth))/(R^2)` Newton gravitation law
where `G=6.67*10^(-11) m^3/(kg*s)`, `R=1.5 *10^11 m, M_(sun)=2*10^30`
`(G M_(sun) M_(earth))/(R^2)=M_(earth)v^2/R`
`v^2=G M_(sun)/R`
`v=29.8 (km)/s`
`v_(mean)=29,783 (km)/s` sorce: https://en.wikipedia.org/wiki/Earth