The discussion centers on the dynamics of a mass-spring system involving a pulley and two masses. It establishes that if the string is massless and the pulley is also massless, the tension remains equal on both sides, and both masses will accelerate uniformly. However, the presence of friction in the pulley's axle can create a difference in tension, even if the pulley itself is massless. The net force on the string is zero when it is massless, but if the string has mass, the net force is determined by its acceleration.
PREREQUISITESPhysics students, mechanical engineers, and anyone studying dynamics and forces in mechanical systems will benefit from this discussion.
I would word that a little differently. If a section of the string has mass m and acceleration a then the net force on it is ma. If the string is massless then that must be 0.projjal said:If the string is light the net force on it is zero; or else it is accelerating and so there should be some force on it.
Another possibility is that there may be friction in the pulley's axle. (We generally assume there is sufficient friction between the string and pulley to prevent slipping.) This would lead to a difference in tensions even if the pulley is massless.If the pulley is also massless, the tension on both sides will be same.And obviously both the objects will have same acceleration,provided the string is rigid.
Another possibility is that there may be friction in the pulley's axle
haruspex said:Another possibility is that there may be friction in the pulley's axle. (We generally assume there is sufficient friction between the string and pulley to prevent slipping.) This would lead to a difference in tensions even if the pulley is massless.
I do not understand the case when friction is present at the axle and the pulley is massless.
Writing torque equation,(T1-T2)R=Iα .But the R.H.S is zero as I=0.So,T1=T2 .