Pseudo Forces: Non-Inertial Frame of Reference

All masses whose motion is defined by a non-inertial reference frame, such as a rotating reference frame, experience a pseudo force, also known as an inertial force, fictitious force, or d’Alembert force. When a frame of reference accelerates relative to a frame that is not speeding, pseudo force is created.

Pseudo Force

Without any physical interaction between the two objects, the acceleration ‘a’ of the non-inertial reference frame alone generates the force F. Like frames, pseudo forces are free to accelerate in any direction (but only in direct response to the acceleration of the frame).

Four pseudo forces for frames accelerated in typical methods are defined:

• A relative acceleration of the origin in a straight line, or rectilinear acceleration, produces one force
• Coriolis force and centrifugal force are two forces that rotation produces
• The fourth component, the Euler force, is brought on by a variation in rotational speed

Pseudo implies something that is made up, fictional, or nonexistent but that we nonetheless take into consideration. When we push, pull, or roll an object over a surface, we are applying a force.

When we discuss pseudo force, we are referring to a hypothetical force. Although it doesn’t exist, we still regard it as a necessary component in the study of the nature of forces in physics. 

A pseudo force is always opposite to the direction as the acceleration of an object’s frame of reference. In other words, as the frame of reference of an item accelerates, a pseudo force will always act in the opposite direction. You may already be aware that Newton’s second law controls motion. An object’s mass and acceleration determine the net force acting on it. (For instance, F_net = ma.) Similar to this, we may write the pseudo-force formula as follows:

Pseudo force formula: F_p = – ma

here  F_p is the pseudo force acting on an object, m is the mass of an object, and a is the acceleration of an object frame of reference.

Non Inertial Reference Frame

A frame of reference that does not obey the law of inertia is called non-inertial. There is no net force driving the ball’s acceleration, even though it is moving faster toward the front of the bus. A frame of reference that accelerates relative to an inertial frame is referred to as a non-inertial reference frame.  In general, an accelerometer at rest in a non-inertial frame will detect an acceleration that is greater than zero. In non-inertial frames, the rules of motion differ from frame to frame depending on the acceleration, but they remain the same in all inertial frames.  In classical mechanics, it is frequently possible to use the addition of fictitious forces (also known as inertial forces, pseudo-forces, and d’Alembert forces) to Newton’s second law to describe the motion of bodies in non-inertial reference frames. The Coriolis force and centrifugal force are two prevalent instances of this. In general, the acceleration of the non-inertial frame can be used to derive the formula for any fictional force. According to general relativity theory, frames are locally inertial but globally non-inertial due to the curvature of spacetime. In general relativity, there are no global inertial reference frames because of the non-Euclidean geometry of curved space-time. The force of gravity is the fictional force that appears in general relativity, to be more precise.

Non Inertial Frame of Reference Examples

A non-inertial reference frame is one that is revolving around an axis or accelerating linearly.

Examples: A train travelling at a fixed speed is an example of inertial referencing frames. An automobile that is spinning while moving at a constant speed.

Conclusion

A pseudo force is a made-up force that seems to act on a mass whose motion is represented by a frame of reference that is not inertial. Four pseudo forces for frames accelerated in typical methods are defined. The Rectilinear Acceleration, Coriolis Force, Centrifugal Force, and Euler Force are the four forces. Pseudo forces include, but are not limited to, lifts rising and cars moving forward. An object at rest and an object in motion both remain in motion unless acted upon by a net force in inertial reference frames, where Newton’s first law of motion is valid. Inertial reference frames are either stationary or move continuously.