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

The velocity of earth revolves around the sun = `v = 30 kms (or) 30 xx 10^(3) ms^(-1)`
K.E of the earth = `1/2 mv^2 = ?`
Mass of the earth = `5.9 xx 10^(24) kg`
K.E = `1/2 xx 5.9 xx 10^(24) xx 30 xx 30 xx 10^(+3) xx 10^(+3)`
`1/2 xx 5.9 xx 10^(24) xx 900 xx 10^(6)`
`= 2655 xx 10^(30) (or) 26.55 xx 10^(32) J`
`T.E = P.E + K.E`
`= -49.84 xx 10^(32) + 26.55 xx 10^(32)`
`E = -23.29 xx 10^(32) J`.