想問一下 點解after a sharp push , the trolley moves down the runway at a
constant speed ,唔係加速/?
friction compensated runway
2010-08-22 4:21 am
回答 (2)
2010-08-22 5:24 am
✔ 最佳答案
首先你要知道 friction compensated runway 的原理：由於斜台有一定的角度，令架車受到一個向下的weight component，mg*sin a，而這個力剛好是抵消了斜台表面對架車所造成的摩擦力，因此架車after a sharp push之後再沒有net force acting on the trolley，咁根據Newton's 1st Law，架車會以constant speed 前進直到架車行完成個 friction compensated runway為止。 
2010-08-22 10:36 pm
friction compensated runway 是指 component of weight is balanced by friction of the runway. (i.e.mgsin@=f)
since net force acting on trolley is 0,by newton first law of motion,the trolley move with constant velocity.
since net force acting on trolley is 0,by newton first law of motion,the trolley move with constant velocity.
收錄日期: 2021-04-13 18:50:36
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20100821000051KK01410