The earth’s orbit is oval in shape . explain how the magnitude of gravitational force between earth and sun changes as earth moves from position p to q as shown in the figure.

The gravitational force does change believe it or not, but the explaination for this is because the earths orbit is an oval (or a not circle) the closer it nears its self to the sun. the suns gravitational pull, pulls the earth to it bringing it closer and as it reaches the other side lets call this L when it reaches L it becomes the same gravitational pull reset as P is and another section over the sun lets call this M and when it reaches M its the same pull as Q, you get it now?

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multiply 2kg by latent heat of vap