There is a hole in a metal disc . What happens to the size of the hole if metal disc is heated?

A disc of radius R is rotating with an angular speed omega_0 about a horizontal axis. it is placed on a horizontal table. The coefficient of kinetic friction is mu_k . Which force is responsible for the effects in what happens to the linear velocity of a point on its rim when placed in contact with the table? and What happens to the linear speed of the centre of mass when disc is placed in contact with the table?

A hole is drilled in a copper sheet. The diameter of the hole is 4.24 cm at 27^@C . What is the change in the diameter of the hole when the sheet is heated to 227^@C ? Coefficient of linear expansion of copper = 1.70 xx 10^5 ^@C^-1 .

If the intensity of incident radiataions on a metal is doubled, what happens to the K.E. of electrons emitted.

What is metallic character?

What is the moment of inertia of a disc about their diameters?

Metal rod on heating:

A circular copper disc 10 cm in radius rotates at 20pi rad/s about an axis through its centre and perpendicular to the disc. A uniform magnetic field of 0.2 T acts perpendicular to the disc. What is the induced current if the resistance of the disc is 2Omega ?