Why didnt people bieleve in galileos discoveries

Because the church said he was lying and at the time the church was the head of science so if the church said it was true Galileos discoveries did not go with the church's so they sentenced him to death

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