Question

Which of the following is not an example of contact force.
a) Muscular Force
b) Gravitational Force
c) Frictional Force
d) None

Answer 1

Hint: Muscular force and Frictional force requires touch between the object and its covering, thus they are an instance of contact force. While magnetic and gravitational forces do not need contact between the two objects and so are named non-contact forces. These forces are pulled even if the two objects are divided by a distance r.

Complete step-by-step solution:
Muscular power is the power applied to utilize parts of the body like legs or arms. It is a force that occurs because of the movement of muscles and is a contact force since there is a connection between the surfaces. Muscular force is needed whenever the action of the body occurs. Strolling, getting up from a seat, lifting, crossing a leg, and so on all need muscular force.
Gravitational force is capable of bringing the things we throw into the air back to the earth. When an object is put on a surface, it applies a downward force equivalent to its weight, and this downward force is identified as Gravitational force. The gravitation is an attraction that lives between all objects that have mass. The sun's gravitational force holds the Earth and all the other solar system planets in a fixed orbit. Gravitational force does not require to be in connection to apply its downward force. A non-contact force is implemented to an object by a different body that is not in direct contact. Non-contact forces are when objects do not have a physical connection between them or when a force is concerned without any interaction. Gravitational force is a non- contact force.
The force that always resists one body's motion above another body is identified as a frictional force. It operates between the two surfaces, which are in connection with each other. The frictional force always operates on all the traveling objects, and its direction is always reversed to the direction of motion. Since frictional force results when two objects' surface is in connection with one other, frictional force is an example of contact force.
Option (b) is correct.

Note: Contact force is a force that is implemented by objects in touch with each other. The contact force acts on the point of direct touch between the two objects. A non-contact force is implemented to an object by another body that is not in direct touch. Non-contact forces come into play when bodies do not have physical touch between them or when a force is implemented without any interaction.