Why is centrifugal force called a 'pseudo'-force? Give descriptive answer please (not many equations) I am an Honours student but still I don't understand this. I mean, how can a force be called 'pseudo' when we can really feel it? For example, while we are on a merry-go-round, we all feel a force pushing us outward. How can such a force be called pseudo, just because our mathematical descriptions don't account for it? A more descriptive (rather than explanation by equations) is needed.
 A: Basically, the difference lies in the fact that being in a merry go round, there is no way to tell that you are rotating yourself, i.e. you base your observation with the assumption that you are stationary in your frame, which is inside the merry go round. Hence all you see observe that you are mysteriously pushed outwards (when you actually shouldn't, in your reference frame). To explain your observation, you hence attribute a force called the "centrifugal force".
Now another person, standing in the park observing the merry go round rotating, isn't amused a bit by this pushing "outwards". He can very well explain this phenomenon by stating the centripetal force of the merry go round due to its rotation, which keeps you in a circular motion, instead of you flinging out in a linear direction. 
The force described by the person standing in the park, i.e. "centripetal force" is real because he can explain what causes it (i.e. the rotation of the merry go round).
On the other hand, for you, this "centrifugal force" is absolutely required to explain your dilemma, but you have no idea why this is caused. (Note: remember, being in the frame of the merry go round, you have no way of telling that it is rotating). Hence this force isn't real, you can't say what causes it. But from your perspective, you need it to describe your observation. 
Hence the "centrifugal force" isn't real, it's a pseudo - force. I hope this explanation was able to make things simpler!
A: 
For example, while we are on a merry-go-round, we all feel a force pushing us outward.

No, one feels a force pushing oneself inward, not outward. That inward centripetal force is real. The only other real forces acting on a person riding a merry-go-round are the upward normal force and the downward gravitational force. There is no real force pushing the person outward.
When looked at from the perspective of a frame rotating with the merry-go-round, the person riding the merry-go-round is stationary. The real inward centripetal force still exists; real forces in Newtonian mechanics are present in all frames of reference. Explaining that stationarity from the perspective of Newton's second law requires the fiction of a centrifugal force. Fictitious forces are a result of insisting on using Newton's second law in a context where Newton's second law doesn't quite apply. There's nothing wrong with that; this formation extends Newton's second law from inertial frames to non-inertial frames.
However, it is important to keep in mind that those fictitious forces are not real.
A: You do not really “feel” a pseudo force, you only need it to justify why the effect of the other forces fail to explain the motion according to newton’s laws (or according to your regular experience on inertial frames if you do not know newton’s laws). For instance, in the merry go round you only experience the centripetal force, the one made by being in contact with the physical object. In your rotating frame of reference you experience this force, but you do not  move, so you explain to yourself that it must be because there is also an outward force that stops you from moving. Due to your inertia you try to keep moving outwards but the merry go round stops you from doing that. That is why it looks like a force. However, if you jump up while in a merry go round, you will start moving at constant speed outwards, you will not experience any acceleration.   
A: In a rotating reference frame Newton's laws fail. To quote Newton's first law from wikipedia:

1) In an inertial frame of reference, an object either remains at rest or
  continues to move at a constant velocity, unless acted upon by a
  force.

Imagine you are on the merry go round and place a ball on the ground. The ball will start rolling away from the center. The ball is accelerating but there is no force that causes this acceleration. You might wonder "What do you mean there is force? That's just the centrifugal force!" To see this is not a proper force take a look at Newton's third law

3) When one body exerts a force on a second body, the second body simultaneously exerts a force equal in magnitude and opposite in direction on the first body.

Or more succinctly 'for every action there is an equal but opposite reaction'. In the frame of the merry go round there is no force that is equal and opposite to this centrifugal force. This would mean momentum is created from nothing and would violate momentum conservation. So aside from the fact that is causes an acceleration, this is not a proper force. That's why you call it a pseudo-force. 
Newton's laws can predict many, many things in nature but it has some fundamental flaws. Because the frame of the merry go round has pseudo-forces and the stationary frame has none you would call this stationary frame the 'right' frame. But there isn't actually a 'right' frame in the universe. The stationary frame is still on the earth, so it experiences Coriolis forces because the earth also rotates. You need General Relativity to solve this issue. In General Relativity there are no preferred frames of references. I don't actually know rotating frames work in General Relativity so I hope this is enough to answer your question.
A: @WRICHIK's book explains it fairly well.
If your frame of reference is rotating, then the object fixed at radius R is stationary, it is not accelerating toward the center.
Yet if it were attached to a scale it would show a force.
If it were then detached, it would then feel no force but it would accelerate away.
How is that possible, to have acceleration but no force?
So forces measured in a non-inertial frame are confusing and are called "pseudo".
Real forces are things that cause acceleration.
A: It's an issue of cause and effect.  Forces cause motion to change, and the effect is the motion changes (either by speeding up/slowing down or changing direction).
There are four common forces we deal with in introductory physics classes: Friction/Traction, Gravity, Normal and Compression/Tension.  "
When a rock is swung around in a circle by a chord, the tension in that chord is what causes the rock to move in a circle.  The cause is the tension.  The effect is the circular motion.
When a satellite is in circular orbit around the Earth, the cause of the circular motion is gravity, the effect is that circular motion.  Without gravity, the satellite would move in a straight line, at constant speed.
When a car makes an unbanked turn, the friction/traction is the thing that allows the car to make that turn.  If the car is on slick ice, the friction/traction is minimal, and the car isn't able to change its motion.
When people talk about a "centrifugal force", they are talking about an effect, not a cause.  Since circles are so nice, its natural to think that circular motion is a usual state of affairs, one that doesn't need to be explained.  But any deviation from moving in a straight line, at constant speed must be explained by a cause.  So circular motion has to be caused by an inwards force, typically one that's on our list.
A: You may refer to these two pages of the physics book which we use in higher school in India:


