Q66 of 149 Page 195

The pulley shown in figure (10-E11) has a radius of 20 cm and moment of inertia 0.2 kg-m2. The string going over it is attached at one end to a vertical spring of spring constant 50 N/m fixed from below, and supports a 1 kg mass at the other end, the system is released from rest with the spring at its natural length. Find the speed of the block when it has descended through 10 cm. Take g= 10 m/s2.



Given:


Moment of inertia (I) = 0.2 kg-m2


Radius of the pulley (r)= 20cm


Spring constant (K)= 50 N/m


Mass of the block (m)= 1 kg


Height from which it starts descends (h)= 10cm


using law of conservation of the energy






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