Virtual displacement for a block sliding down a wedge

[Kashmir]

A block slides on a frictionless wedge which rests on a smooth horizontal plane. There are two constraints in this system. One that the wedge can only move horizontally and another that the block must remain in contact with the wedge.

We want to find the virtual displacements for the two block system.

To find those virtual displacements we imagine to freeze the constraints and look for the possible displacements.

Now if I freeze the constraints then the wedge cannot move. The only possible motion is that the small block slides parallal along the incline. However I have found on many articles online that there is a virtual displacement for the wedge as well.

This confuses me how to view the virtual displacements in this case. Can anyone please explain this. Thank you.

 

[CWatters]

Imagine what happens if the small block is constrained to move vertically downwards. The wedge would be squeezed and pushed to the left. Similar to squeezing a slippery melon seed between fingers.

 

[haruspex]

Imagine what happens if the small block is constrained to move vertically downwards. The wedge would be squeezed and pushed to the left. Similar to squeezing a slippery melon seed between fingers.

I don't think that helps with the question being asked, namely, how one is supposed to apply the method of virtual displacement here.
It's not a method I am au fait with, so I won't attempt to write an answer.
@Kashmir , see if page 31 onwards of https://www.worldscientific.com/doi/pdf/10.1142/9789810248154_0002 helps.

 

[Kashmir]

I don't think that helps with the question being asked, namely, how one is supposed to apply the method of virtual displacement here.
It's not a method I am au fait with, so I won't attempt to write an answer.
@Kashmir , see if page 31 onwards of https://www.worldscientific.com/doi/pdf/10.1142/9789810248154_0002 helps.

Thankyou. I'll check it