Q. A string of negligible mass going over a clamped pulley of mass supports a block of mass as shown in the figure. The force on the pulley by the clamp is given by Physics Question Image

 7122  227 IIT JEEIIT JEE 2001Laws of Motion Report Error

Solution:

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Free body diagram of pulley is shown in figure. Pulley is in equilibrium under four forces. Three forces as shown in figure and the fourth, which is equal and opposite to the resultant of these three forces, is the force applied by the clamp on the pulley (say ). Resultant of these three forces is

Therefore, the force is equal and opposite to as shown in figure.
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