假如沒有摩擦力,我們生活上會遇到甚麼困難?

wow, it's a very interesting topic.....sorry, i could not write in chinese...

1. we have difficult to move forward/backward/stop......motion needs elements like force direction, gravity; we need friction to change our force direction.

2. all object will fall to ground on imbalance table, shelf, etc.......nothing could hold object to stay on even very little slope surface.

3. car can not move or once move, it has difficult to stop.....no friction between floor and tire

4. we can not open bottle since we could not twist open the top cap.....it need friction between our hand and bottle to hold it for twisting

5. people easy to fall down ....since we need friction between foot and floor to maintain balance, otherwise, just like standing on ice surface (that's why the floor need to be irregular)

6. teacher could not use chalk to write .....it need friction between blackboard and chalk for leaving the chalk mark on board.

7. student could not write on pen/pencil .....similiar to above reason

8. we could not wash our cloth clean, even could not wash our body clean....we need friction between cloth/towel to remove dirts.

假如沒有摩擦力，慣性地前進的東西便不能停止。

沒有了摩擦力 我們不能在路面上行走, 汽車不能加速...............
so we cannot do something