Contact Forces Elastic force(弹力) 人Λ人人入OF 0 Hook's Law F=-kx K:force constant
Contact Forces Elastic force（弹力） F k x 0 x F Hook’s Law K : force constant
Friction Kinetic Friction(滑动摩擦力) mg f=uN u:the coefficient of kinetic Friction
Friction Kinetic Friction（滑动摩擦力） f N : the coefficient of kinetic Friction v f N mg