Assume that Earth is in circular orbit around the Sun with kinetic energy K and potential energy U, taken to be zero for infinite separation. Then, the relationship between K and U:

Options

A. is K=U
B. is K = −U
C. is K = U/2
D. is K = −U/2

Answer

D

Explanation

For earth to orbit in circular path
`(GMm)/R^2=(mv^2)/R rArr mv^2 =(GMm)/R`
`K.E.=1/2mv^2=1/2(GMm)/R =K`
P.E.=`-(GMm)/R=U` , Hence , `K=-U/2`