Pseudo Force - Definition, Explanation, FAQs

Pseudo force is a force which converts non inertial frame of reference to inertial frame of reference. Where, pseudo meaning is false or fictitious and hence it is also known as false force. Pseudo meaning in Hindi is मिथ्या, pseudo meaning in Tamil is போலி and pseudo meaning in Telugu is నకిలీ. Similarly, fictitious meaning in Hindi is काल्पनिक, fictitious meaning in Tamil is கற்பனை and fictitious meaning in Telugu is కల్పితమైనది. To understand what is pseudo force? First we have to learn about inertial frame of reference and non-inertial frame of reference.

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Inertial Frame Of Reference

Inertial frame of reference is a frame of reference, either at rest or moving with a constant velocity. Consider a boy standing on a ground observing and a particle stays at rest as seen in a frame. Also, if he is moving with constant velocity v then the frame of reference is said to be inertial frame of reference.

Or

In which newton’s laws of motion hold upright. A frame at rest or moving with constant velocity with respect to an inertial frame.

Non Inertial of Reference

Non inertial frame of reference is a frame of reference moving with non zero acceleration. Newton’s laws of motion are not effective in Non inertial frame of reference. Consider a boy observing a block, he is sitting in a car which is moving with an acceleration a as the frame of reference is also moving with an acceleration a then the frame of reference becomes non inertial.

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Frames of reference which have acceleration or rotation with respect to an inertial frame are Non inertial. When observer was not able to explain the motion of the object using newton’s laws of motion in some specific conditions, this was taken as a challenge. The solution to this challenge came in form of an imaginary force known as pseudo force. What is pseudo? What is the meaning of Pseudo? Pseudo force meaning is fictitious or false. Fictitious meaning in Bengali is কাল্পনিক. whenever an observer is in Non inertial frame of reference, he is not able to explain the motion as per newton’s first or second law of motion and need to consider an imaginary force. Imaginary force is also known as fictitious force or pseudo force. And in case of circular motion it is known as centrifugal force. Why centrifugal force is called pseudo force? To answer this question let us explain pseudo force in detail.

Pseudo Force Explanation

Pseudo force is a fake or imaginary force. In order to understand and to define pseudo force, let us consider the following situation.

There is a railroad card standing on a railway track. There are two observers, one is standing on the railroad cart while the other one is standing on the ground. Now, suppose the cart starts to accelerate towards right. For the observer on the ground, situation is very simple. The cart has started accelerating, so cart along with the observer on the cart are moving ahead with some acceleration. The motion of the cart has no effect on the rocks scattered on the ground. This observation is in accordance with the newton’s laws of motion. There is no horizontal force acting on the rocks, so the rocks are at rest. But for the observer on the cart, situation is more complicated. Since, he is standing on the cart, to him the cart will appear to be at rest. But the rocks and the ground will appear to be moving backward with the same acceleration as the acceleration of the cart. For him the newton’s laws of motion is being violated here. The rocks are moving without any horizontal force. Alternatively we can say that to the observer on the cart, it will appear as if there are some forces acting on the rocks in backward direction and because of these forces everything is accelerating in backward direction. Of course there is no force, rocks appear to move only because the observer himself is accelerating. But in the frame attached to the cart, there appears to be a force acting in opposite direction on all the objects. This force is called pseudo force.

Pseudo means false. Thus it is a false force. It does not really exist, it appears only when our frame of reference is accelerating. In other words, whenever we are analysing a situation from a frame that is accelerating. All bodies in that frame will experience an extra force that is the pseudo force. When your frame of reference is accelerating in forward direction, all objects will appear to be accelerating in backward direction. Therefore, the direction of pseudo force is always in direction opposite to the direction of acceleration of the frame. Also, if the frame is accelerating with acceleration 'a', all the objects at rest will appear to be moving with acceleration 'a' in backward direction. So, the apparent force must be equal to the product of mass of an object and acceleration of the frame. Then only it will be able to satisfy newton's second law of motion. Pseudo force is a force which converts non inertial frame of reference to inertial frame of reference.

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Pseudo force formula,

F(p) = mass x acceleration

Where F(p) is pseudo force.

Hence, the magnitude of pseudo force is always equal to the mass of an object into the acceleration of the frame. Here the acceleration of a particle is seen from two frames. To summarize, pseudo force does not really exist. It is only a trick or tool used to solve complicated problems where our object under consideration is inside a moving frame. It appears only when our frame of reference is accelerating. Its direction is always opposite to the direction of acceleration of the frame and its magnitude is always equal to the product of mass of the object and acceleration of the frame. Pseudo force is not absolutely necessary to solve the questions. Every question that require pseudo force to solve can be solved without using pseudo force also. But in some case, solving using pseudo force is more efficient.

Hence we can say that centrifugal force is a pseudo force since it is not provided by any real force. It is originated from the accelerated frame of reference that is non inertial frame of reference. Now let us distinguish between pseudo force and real force. Real force are the force which are exerted by an object or particle in real life and that does not violates newton’s laws of motion. On the other hand pseudo force are the force which does not really exist in real life but it is only a trick or tool used to solve complicated problems where our object under consideration is inside a moving frame.

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