does friction restrict motion perpendicular to the plane also??
Friction is caused due to cold weld between the molecules of the surface and the object.So why does it only affect the motion parallel to surface. Because even when we move a body straight up the cold weld needs to be broken.
Sorry for writing in abbreviated style...!
But my question is that any thing in this universe has energy...so cannot energy be the fundamental constituent of universe...
I've read everywhere that strings are now taken to be the fundamental particle, but I think that it is taken as one because we cannot go further. After a few years once we can go in we may discover a new elementary particle.
I was thinking; isn't energy the fundamental particle? Because even...