Question 195: Laws of Motion

Question

Which one of the following is 'NOT' a contact force?

Accepted Answer

Option C, Gravitational force, is 'NOT' a contact force.
Contact forces require physical contact between objects, including:
Force of friction
: This is a contact force that opposes the relative motion or tendency of such motion of two surfaces in contact.
Normal reaction
: A contact force exerted perpendicular to the surfaces in contact, often experienced as the support force from a surface.
Viscous force
: Another contact force, occurring between layers of fluid in motion relative to each other.
In contrast, a gravitational force is a non-contact force that acts at a distance, pulling two masses toward each other without needing any direct physical interaction. The mathematical expression for gravitational force between two masses $ m_1 $ and $ m_2 $ separated by a distance $ r $ is given by:
$$ F = \frac{G m_1 m_2}{r^2} $$
where $ G $ is the gravitational constant. This formula shows how gravitational force operates over a distance, not requiring objects to touch or interact directly.

Answer

Force of friction.

Answer

Normal reaction.

Answer

Gravitational force.

Answer

Viscous force.

Laws of Motion

Which one of the following is 'NOT' a contact force?

Choose the correct answer: