A 14.5 kg mass, fastened to the end of a steel wire of unstretched 1.0 m, is whirled in a vertical circle with an angular velocity of 2 rev/s at the bottom of the circle. The cross- sectional area of the wire is `0.065" cm"^(2)`. Calculate the elongation of the wire when the mass is at the lowest point of its path.

A stone tied to one end of a string of radius 0.6m is whirled in a horizontal circle with an angular speed of 120rpm. Calculate the radial acceleration and force exerted by the stone of mass 0.010 kg on the agent.

i] List the differences between electrical resistance and resistivity of conductor. ii] A copper wire of resistivity 1.63xx10^(-8)Omega-m has cross section area of 10.3xx10^(-4)cm^(2) . Calculate the length of the wire required to make a 20Omega coil.

A current of 5A is passing through a metallic wire of cross-sectional area 4 xx 10^-6 m^2 . If the density of the charge carriers in the wire is 5 xx 10^26//m^3 , find the drift speed of the electrons.

A block of wood of mass 0.5 kg is suspended by means of a thin wire. A bullet of mass 0.020 kg is fired horizontally in the plane of the block with a velocity of 100ms^(-1) . If the bullet gets stuck inside the block, then calculate the height by which the system rises (g=9.8ms^(-2)) . Calculate the amount of heat produced in the block.

A current of 5 A is passing through a metallic wire of cross- sectional area 4 xx 10^(-6) m^(2) . If the density of charge carries of the wire is 5 xx 10^(26) m^(-3) , the drift velocity of the electrons will be