A cord is wound over the rim of a flywheel of mass 20 kg and radius 25 cm. A mass 2.5 kg attached to the cord is allowed to fall under gravity. The angular acceleration of the flywheel is

A cord is wound over the rim of a flywheel of mass 20 kg and radius 25

1.	A cord is wound over the rim of a flywheel of mass 20 kg and radius 25 cm. A mass 2.5 kg attached to the cord is allowed to fall under gravity. The angular acceleration of the flywheel is
Answer» `25 rad//s^(2)` `20 rad//s^(2)` `10 rad//s^(2)` `5 rad//s^(2)` Solution :Moment of inertia of FLYWHEEL about its AXIS , `I = (MR^(2))/(2) = ((20 kg) (25 xx 10^(-2) m)^(2))/(2)` `= 25 xx 25 xx 10^(-3) kg m^(2)` Torque acting on the flywheel , `TAU = FR = mg R ` `= (2.5 kg) (10 m//s^(2)) (25 xx 10^(-2) m)` `=25 xx 25 xx 10^(-2) Nm` ANGULAR acceleration of the flywheel , `ALPHA = (tau)/(I) = (25 xx 25 xx 10^(-2))/(25 xx 25 xx 10^(-3)) = 10 "rad/s"^(2)`