Earth revolves around the sun at 30 km`s^(-1)` calculated the kinetic energy of the Earth.What is the total energy of the Earth in that case? Is the total energy positive?Give reasons.(Potential energy of earth = `-49.84xx10^32)`

Explanation

Mass of the Earth `M_(E) = 5.9 xx10^(24 kg`
Speed of the Earth rovolves around the sun
`V_(E) = 30 " k ms"^(-1)`
Kinectic energy of Earth `E_(K ) = 1/2 M_(E) V_(E)^(2)`
`E_(K) = 1/2 xx 5.9 xx10^(24) xx (30 xx10^(3))^(2)`
` = 1/2 xx 5310 xx10^(30) = 2655 xx10^(30)`
`E_(K) = 2.655 xx10^(33) ` joule (or)J
Total energy of theEarth , E = Kinetic energy + Potential energy
` = 1/2 MV^(2) (-(GM_(1)M_(2))/(r^(2)))`
` = 2.655xx10^(33) +(-4.985 xx10^(33))`
` = 2.655 xx10^(33) - 4.985 xx10^(33)`
`E = - 2.33 xx10^(33) ` joule (or) J