List of top Physics Questions on Mechanics and wave Motion

A wooden plank of mass 90 kg and length 3.3 m is floating on still water. A girl of mass 20 kg walks from one end to the other end of the plank. The distance through which the plank moves is
When the load applied to a wire is increased from 5 kg wt to 8 kg wt, the elongation of the wire increases from 1 mm to 1.8 mm. The work done during the elongation of the wire is (Acceleration due to gravity = 10 m/s2^2):
Two bodies A and B of masses 2m 2m and m m are projected vertically upwards from the ground with velocities u u and 2u 2u respectively. The ratio of the kinetic energy of body A and the potential energy of body B at a height equal to half of the maximum height reached by body A is:
The vibrations of four air columns are shown below. The ratio of frequencies is:
The vibrations of four air columns
When a wave enters into a rarer medium from a denser medium, the property of the wave which remains constant is: