[Physics] Power

chungundertaker

上次Chem已經解決左,唔該曬先
今次到physics
A 25.0 child on a 2.00-m-long siwng is released from rest when the ropes of the swing make an angle of 30.0度 with the vertical.
(a) neglecting the friction, find the child's speed at the lowest position.
(b) if the actual speed at the lowest position is 2.00m/s, wht is the mechanical energy lost due to friction.
Thx all for help first

2076

你Form幾

chungundertaker

原帖由 2076 於 2006-10-15  04:13 PM 發表
你Form幾

其實...我讀緊加拿大year 1,但要take翻college physics
physics真係唔楠掂
救我呀

chungundertaker

呢條解決左了
仲有一條
A 50.0kg student climbs a 5.00m long rope and stops at the top
(a) What must her average speed be in order to math the power output of a 200-W light bulb
(b) How much work does she do
physics真係唔係好掂
高手救我呀

ken809

1.P=Fv
自己諗下個F係幾多啦
2.W=Fs
計到個F, 你唔會唔知個s係咩黎掛

chungundertaker

原帖由 ken809 於 2006-10-15  05:03 PM 發表
1.P=Fv
自己諗下個F係幾多啦
2.W=Fs
計到個F, 你唔會唔知個s係咩黎掛

Ken哥,請受我一拜

ken809

原帖由 chungundertaker 於 2006-10-15  05:10 PM 發表

Ken哥,請受我一拜

唔敢...