kinetic energy....

[lmf22]

The Earth's distance from the sun varies from 1.474e8 km to 1.525e8 km during the year. Take the Sun to be at rest.

Determine the difference in the Earth's kinetic energy.

Would I just use K=.5mv^2? If so what would v be?
If not, how would I set this up?

Thank you.

[Doc Al]

Find the change in gravitational potential energy.

[Leong]

i think so.
Newton's law of universal gravitation to find a.
Motion in circular path although the orbit is an ellipse to relate a and v.