As observed from the earth, the sun appears to move in an approximately circular orbit. For the motion of another planet like mercury as observed from the earth, this would:
 

Different points in the earth are at slightly different distances from the sun and hence experience different forces due to gravitation. For a rigid body, we know that if various forces act at various points in it, the resultant motion is as if a net force acts on the centre of mass causing translation and net torque at the centre of mass causing rotation around an axis through the CM. For the earth-sun system (approximating the earth as a uniform density sphere):
 

Choose the wrong option.
 

Particles of masses 2M, m and M are respectively at points A, B and C with $AB=\frac{1}{2}\left(BC\right)$. The mass m is much-much smaller than M and at time t = 0, they are all at rest as given in the figure. At subsequent times before any collision takes place,

1. m will remain at rest.

2. m will move towards M.

3. m will move towards 2M.

4. m will have oscillatory motion.

There have been suggestions that the value of the gravitational constant G becomes smaller when considered over a very large time period (in billions of years) in the future. If that happens, for our earth,
 

Choose the correct alternatives:

1. (a, c)

2. (a, d)

3. (c, d)

4. (a, b)