Dynarnics Geometrical constraint: y=r, Constraint of motion: VA-ro=0, (ro=o) (2) Steady constraints and unsteady constraints A constraint which is time-dependent is called an unsteady constraint. A constraint which does not depend on time is called a steady constraint In the examples above the constraints do not change with the time, so they are all steady constraints For example, the object M is made of a x fixed ring and a rope tied to the ring. At the beginning, the length of the single pendulum is lo, drag the rope with uniform speed v. In the equation of the constraint, x2+y2=(l o vt 2, the time t appears directly. I11 Geometrical constraint: Constraint of motion: ( 0). 0, , − = − = =   x r  v r y r A A A A constraint which is time-dependent is called an unsteady constraint. A constraint which does not depend on time is called a steady constraint.In the examples above, the constraints do not change with the time, so they are all steady constraints. (2) Steady constraints and unsteady constraints For example, the object M is made of a fixed ring and a rope tied to the ring. At the beginning, the length of the single pendulum is l0 , drag the rope with uniform speed v. In the equation of the constraint, x 2+y2=( l0 - vt ) 2 , the time t appears directly