Atomic Structure

A spectroscopic instrument can resolve two nearby wavelengths and if is smaller than 8,000. This is used to study the spectral lines of the Balmer series of hydrogen. Approximately how many lines will be resolved by the instrument?

Vector

A carrom board (4ft x 4ft) has the queen at the centre. The queen, hit by the striker moves to the front edge, rebounds and goes in the hole behind the striking line. Find the magnitude of displacement of the queen from (a) from the centre of the front edge, (b) from the front edge to the hole and (c) from the centre to the hole.

The solution is embedded as part of live recording done during a class.

Rolling Friction

Rolling friction is due to the deformation taking place at the surface of a rolling ball. It is responsible to decrease the velocity of the centre of mass of the rolling ball and hence plays a part in stopping the ball.