What is a pseudo-force and how does it relate to non inertial reference frames?

[sankarshana016]

So I was told that a pseudo-force acts on a body when its's motion is analysed with respect to a non inertial reference frame. I'm a bit confused. Does that mean the reference frame is accelerating with respect to the body, or with respect to the earth? And why does there have to be any sort of pseudo force?

 

[Nugatory]

So I was told that a pseudo-force acts on a body when its's motion is analysed with respect to a non inertial reference frame. I'm a bit confused. Does that mean the reference frame is accelerating with respect to the body, or with respect to the earth?

Neither. It means that an object at rest in that coordinate system is accelerating relative to an object in free-fall.

 

[dauto]

may be an example might help. Imagine you're in a Bus and it starts accelerating. You will feel like you're being pulled to the back of the bus. In fact you're not being pulled at all and the bus instead is accelerating forward. The bus is the non inertial frame since it is accelerating and the illusion that you're being pulled to the back of the bus is the pseudo-force.