Question

the question is attached below

Answer 1

friction Friction is the force resisting the relative motion of solid surfaces, fluid layers, and material elements sliding against each other. There are several types of friction: Dry friction is a force that opposes the relative lateral motion of two solid surfaces in contact.

Answer 2

• Friction is the force resisting the relative motion of solid surfaces, fluid layers, and material elements sliding against each other. There are several types of friction: Dry friction is a force that opposes the relative lateral motion of two solid surfaces in contact.
• When we rub hands friction is produced between our hands which in turns produces heat. This causes us to feel warm.
• Advantages of friction:
• Friction enables us to walk freely.
• It helps to support ladder against wall.
• It becomes possible to transfer one form of energy to another.
• Objects can be piled up without slipping.
• Breaks of vehicles work due to friction.
• It always resists the motion, so extra energy is required to overcome it.
• Disadvantages of Friction:
• Friction Slow Down motion.
• it reduces the efficiency of machine .
• it produces heat which may damage machines.
• it wears out steps of staircase in buildings and foot over bridges.
• it wares out the brake pad of vehicle gradually.
• it wears is out the rubbing machine parts.