Satellites orbiting the earth have a finite life and sometimes debris of satellites fall to the earth. This is because:
 

1.	the solar cells and batteries in satellites run out.
2.	the l2. of gravitation predict a trajectory spiralling inwards.awst
3.	of viscous forces causing the speed of the satellite and hence height to gradually decrease.
4.	of collisions with other satellites.

Both the earth and the moon are subject to gravitational force of the sun. As observed from the sun, the orbit of the moon:
 

In our solar system, the interplanetary region has chunks of matter (much smaller in size compared to planets) called asteroids. They:
 

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.

The following are the given statements:
 

Choose the correct alternatives:

1. (b, d)

2. (a, c)

3. (c, d)

4. (a, c, d)

If the law of gravitation, instead of being inverse square law, becomes an inverse cube law:

Choose the correct alternatives:

1. (a, d)

2. (a, c)

3. (c, d)

4. (b, d)

If the mass of the sun were ten times smaller and gravitational constant G were ten times larger in magnitude. Then,
 

Choose the correct alternatives:
1. (a, b, c)

2. (a, d)

3. (b, c, d)

4. (a, c, d)

If the sun and the planets carried huge amounts of opposite charges, then:

Which of the above statements is/are correct?
1. (a, b, c)
2. (a, d)
3. (b, c, d)
4. (a, c, d)

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)