Question

运动+力学物体质量m=60kg,在水平面上受到与水平面成37度角斜向上的拉力F=20N作用,物体以10m/s的速度做匀速

Answer 1

质量应为6千克吧?

m=6kg

物体匀速运动,Fcos37° = μ(mg-Fsin37°)

动摩擦系数μ = Fcos37°/ (mg-Fsin37°) = 20*0.8/(6*10-20*0.6) = 1/3

撤去外力后,减速度a = μg = 1/3*10 = 10/3

S = v^2/(2a) = 10^2/(10/3) = 30m

力F撤去后物体还能运行30m