Options:
(a) Total kinetic energy of the system remains constant.
(b) Total momentum of the system is conserved.
(c) Both A and B are true.
(d) Neither A nor B are true.
Answer:
(b) Total momentum of the system is conserved.
Explanation:
An inelastic collision is a type of collision in which momentum is conserved and kinetic energy is not conserved. That is, there is loss of kinetic energy.
In an inelastic collision:
Total momentum before collision = Total momentum after collision
An example of inelastic collision is seen in the ballistic pendulum, The ballistic pendulum is a device in which a projectile such as a bullet is fired into a suspended heavy wooden stationary block.
Answer:
Fg = 4.2*10²² N
Explanation:
The gravitational force between any two masses, provided that can be approximated by point masses (comparing their diameters with the distance between them), obeys the Newton's Universal Law of Gravitation, which states that the force (always attractive) is proportional to the product of the masses and inversely proportional to the square of the distance between them (this as a consequence of our Universe being three-dimensional), as follows:

So, if one of the masses increases 6 times, the force between them will be directly 6 times larger, so the new magnitude of the force will be as follows:
Fg₂ = Fg₁*6 = 7*10²¹ N* 6 = 4.2*10²² N