Question

(a) The force exerted by all matter on all other matter is ?
(b) The force which tends to slow down objects or keep them from moving is ?

Answer 1

To answer our question, we will first understand what are the different types of forces in nature. Once we do that, we will check which of the forces satisfies the criteria given in our problem. We will proceed in our solution in this manner to get the required answer.

Complete answer:
There are mainly four fundamental forces that abide in nature. This forces are:
(1) Gravitational Force: The gravitational force between two objects makes use of the mass of the object as a criteria to exert force. If a particle has mass, then it will exert a gravitational force on all other masses containing particles in the universe. It is a non-contact force. This force is exerted by all matter on all other matter.
(2) Weak Nuclear Force: This force exists at atomic level, between the constituent particles, inside the nucleus of an atom. This force is solely responsible for any naturally occurring particle decay in nature. It is a contact force.
(3) Electromagnetic Force: This force acts between charged particles. Like gravity, this is also a type of non-contact force and acts over infinite distance. But unlike gravity, it has two types of base particles, positive charge and negative charge. They follow the rule, unlike charges ‘attract’ and like charges ‘repel’.
(4) Strong Nuclear Force: This is the strongest of the four fundamental forces. For the same distance and mass, a strong nuclear force is ${{10}^{40}}$ times stronger than the gravitational force. But it acts at atomic distances only. This force binds all structures in the universe together.
Now, according to our observation:
(a) The force exerted by all matter on all other matter is Gravitational Force .
(b) The force which tends to slow down objects or keep them from moving is a special kind of electromagnetic force called frictional force.
Hence, gravitational force and frictional force is the correct answer.

Note:
We should always know the fundamental and basics of any topics. These forces combined explain more than 80% of our entire universe’s phenomenon. Also, from the point of view of a question, these are very important as theoretical physics is as important as numerical physics.