關於friction

如果沒有 friction,
1. 我們行路便不會前進, 只能原地踏步, 車輛也不能前進;
2. 前進時便停不了, 直到撞牆;
3. 在斜坡便只有滑下, 停不了, 更不能上山;
4. 桌子上的東西會滑出桌面, 墮下;
5. 拿東西時總會滑出手掌 等等.

你可以再想到其他例子的.

-Wearing shoes can prevent slipping when you walk.
-The grooves on a tyre help to prevent a car from skidding on the road.
-Friction between the box surface snd the match produces heat that can makes the match ignite.
-Friction between the glass and our palm holds the glass in position.

行路,,行車,,
你就咁郁都係friction