What are the structural components of myofibril?

The myofibrils are made up of thick and thin myofilaments, which help give themuscle its striped appearance. The thick filaments are composed of myosin, and thethin filaments are predominantly actin, along with two other muscle proteins,tropomyosin and troponin.

It depends on the surface of the levels. the rougher the surface, the greater is the frictional force. for rougher surfaces, you would need to exert greater force to move the object. the concept is that, you must overcome the frictional force in order to bring the object into motion. this is the reason why we add lubricants to the joints so they could easily move. this answer was on