Sir, please explain » Question A circular plate of uniform thickness has diameter 56 cm. A circular part of diameter 42 cms is removed from one edge. What is the position of the centre of mass of the remaining part? Ans: 9cm » Question A ring and a disc of different masses are rotating with the same kinetic energy. When a retarding torque ' ' is applied on the ring, it stops after making ‘n’ revolutions. In how many revolutions will the disc stop under the same retarding torque? Ans: n » Question Two wheels are connected by a belt. The radius of a larger wheel is three times that of the smaller one. What is the ratio of the rotational inertia of larger wheel to the smaller wheel, when both the wheels have the same angular momentum? Ans: 3 » Question A coin is placed on a gramophone record, rotating at a speed of 45 rpm. It flies away when the rotational speed is 50 rpm. If two such coins are placed one over the other on the same record, both of them will fly away when the rotational speed is: Ans: 50rpm » Question A circular disc 'X' of radius 'R' is made from an iron plate of thickness 't', and another disc 'Y' of radius '4R' is made from an iron plate of thickness 't/4'. Then the relation between the moment of inertia 'I x ' and 'I y ' is: Ans: l y =64l x » Question A tube of length 'L' is completely filled with an incompressible liquid of mass 'M' and closed at both the ends. The tube is then rotated in the horizontal plane at one of its ends with uniform angular speed ' '. What is the force exerted by the liquid at the other end? Ans: MLw 2 /2

Sir, please explain

» Question

A circular plate of uniform thickness has diameter 56 cm. A circular part of diameter 42 cms is removed from one edge. What is the position of the centre of mass of the remaining part?

Ans: 9cm

» Question

A ring and a disc of different masses are rotating with the same kinetic energy. When a retarding torque '' is applied on the ring, it stops after making ‘n’ revolutions. In how many revolutions will the disc stop under the same retarding torque?

Ans: n

» Question

Two wheels are connected by a belt. The radius of a larger wheel is three times that of the smaller one. What is the ratio of the rotational inertia of larger wheel to the smaller wheel, when both the wheels have the same angular momentum?

Ans: 3

» Question

A coin is placed on a gramophone record, rotating at a speed of 45 rpm. It flies away when the rotational speed is 50 rpm. If two such coins are placed one over the other on the same record, both of them will fly away when the rotational speed is:

Ans: 50rpm

» Question

A circular disc 'X' of radius 'R' is made from an iron plate of thickness 't', and another disc 'Y' of radius '4R' is made from an iron plate of thickness 't/4'. Then the relation between the moment of inertia 'I_x' and 'I_y' is:

Ans: l_y=64l_x

» Question

A tube of length 'L' is completely filled with an incompressible liquid of mass 'M' and closed at both the ends. The tube is then rotated in the horizontal plane at one of its ends with uniform angular speed ''. What is the force exerted by the liquid at the other end?

Ans: MLw²/2