Positive SSL
A 25N
B 29N
C 33N
D 37N

P可分解成往下0.6P與往右0.8P(往右是推動物體的力量)

(100+0.6P)×0.2=0.8P

100+0.6P=4P

3.4P=100

P=100/3.4=29.41N