Answer: Friction stops things from sliding apart. If there was no friction everything would slide to the lowest point. With no friction the only possible movement would be falling to a lower point under gravity.
Explanation: In a frictionless world, more objects would be sliding about, clothes and shoes would be difficult to keep on and it would be very difficult for people or cars to get moving or change direction. Students should be encouraged to consider how dependant their world is on the beneficial action of friction. Humans and other objects will become weightless without gravity. If we have no gravity force, the atmosphere would disappear into space, the moon would collide with the earth, the earth would stop rotating, we would all feel weightless, the earth would collide with the sun, and as a consequence.
