PHY問題 /口\

丫蘋果汁丫

al 1998,paper iiA Q3  同 2005,paperiiA,Q3

看似好簡單,,點知自己計上手發覺計唔到答案t^t

趕羚羊

回復 1# 丫蘋果汁丫
98:
Let the required force br F
P-Q=3ma.......(1)
F-Q=2ma.......(2)
(1)/(2):
2P-2Q=3F-3Q
2P+Q=3F
        F=(2P+Q)/3
04:
Let the required distance be x
by s=ut+1/2at^2
     x=5t^2
For t,




        x=Vx (t)
40cosθ=(t)50cosθ
          t=4/5
thus,
     x=5(4/5)^2
       =16/5
       =3.2m