While reading gravitation chapter I got some doubts, and that I am posting here. 1) Is there any meaning of "Weight of the Earth"? 2)At noon, the sun and the earth pull the objects on the earth's surface in opposite direction. At midnight the sun and the earth pull these objects in the same direction. Is the weight of an object as measured by the spring balance on the earth's surface more at midnight as compared to its weight at noon? 3)An apple falls from a tree. An insect in the apple finds that the earth is falling towards it with an acceleration g. Who exerts the force needed to accelerate the earth with this acceleration g? 4)A nut becomes loose and gets detached from a satellite revolving around the earth. Will it land on earth? If yes then where? If no, how can an astronaut make it land on the earth? 5)Is it necessary for the plane of the orbit of a satellite to pass through the centre of the earth? 6)As earth rotates about its axis, a person living in his house at the equator goes in a circular obit of radius equal to the radius of the earth. Why does he/she not feel weightlessness as a satellite passenger feels?