Question

物体A重50N,A与墙间动摩擦因数μ=0.3,现用F=100N 的力压着物体A,此时物体A既不上滑,也不下滑,求物体B的

Answer 1

1.20N--80N

2.a1=g[0.6-0.4]=2

a2=-5

3.f=0.2[20+6]=5.2N

a=[8-5.2]/2=1.4

v=at=7

S1=0.5at2=17.5m

减速时a=-2

S2=v2/2a=49/4=12.25m

S=S1+S2=17.5+12.25=29.75m