Frictional forces are formed when two objects move against each other. These are forces that move in opposite directions, making it harder for an object to move.
Frictional forces are greater on rigid surfaces than on smoother surfaces.
Sometimes, friction is helpful:
However, sometimes friction is not helpful:
Holding Objects – Friction is required to hold onto any object. Without it, objects would slip from your hands.
Using an eraser – When you rub an eraser on paper, it overcomes the frictional force between the lead particles (from the pencil) and the paper.
Polishing rough surfaces – You can use sandpaper to smooth rough or sharp edges. Rough surfaces have more irregularities than smooth surfaces do. The rough and rigid surface of the sandpaper increases friction, which helps to eliminate the irregularities on rough surfaces, making them smoother.
Tug of War – In this game, two teams pull on a long rope. The friction between the players’ hands and the rope helps them maintain their grip.
Forest fires – Trees can rub against each other due to high wind velocities. This builds up friction and heat, which can lead to forest fires.
Climbing trees – There are many animals that have sharp claws, hairy feet or both. These can be used to climb trees. For example, a strong friction exists between the animals’ claws and the tree’s rough surface.