A pseudo force, also known as an inertial force or a fictitious force, is a force that appears to act on an object in a non-inertial frame of reference, such as an accelerating or rotating frame. It is called "pseudo" because it doesn't arise from any physical interaction between objects, but rather from the acceleration of the reference frame itself.

Key Characteristics:

• Non-Inertial Frames: Pseudo forces are only observed in non-inertial frames of reference. An inertial frame is one that is not accelerating or rotating.
• No Physical Origin: Unlike real forces (e.g., gravity, electromagnetism), pseudo forces do not originate from any interaction between objects.
• Mass Dependent: The magnitude of a pseudo force is proportional to the mass of the object it appears to act upon.
• Explains Motion: Pseudo forces are introduced to make Newton's laws of motion applicable in non-inertial frames.

Common Examples:

• Centrifugal Force: When you're in a car turning a corner, you feel pushed outwards. This outward "force" is the centrifugal force, a pseudo force arising from the car's acceleration.
• Coriolis Force: This force affects objects moving on a rotating frame, like the Earth. It deflects moving objects to the right in the Northern Hemisphere and to the left in the Southern Hemisphere and is responsible for the direction of rotation of cyclones. Britannica - Coriolis Force
• Linear Acceleration: If a bus accelerates forward, passengers feel a force pushing them backward. This is a pseudo force due to the bus's acceleration.

Mathematical Representation:

The pseudo force (F_pseudo) is given by:

F_pseudo = - m a_frame

Where:

• m is the mass of the object
• a_frame is the acceleration of the non-inertial frame of reference

The negative sign indicates that the pseudo force acts in the opposite direction to the acceleration of the frame.

Importance:

Pseudo forces are crucial for correctly analyzing motion within non-inertial frames of reference. They allow us to apply Newton's laws consistently, even when the observer is in an accelerating environment. Without considering these forces, predictions about motion would be inaccurate.