Complete :

If the periodic time of an oscillating body is 0.1 sec.. So the number of complete oscillations in one minute is

a - 10
b-600
c-120
d-60

Two particles of masses m and 2m are placed on a smooth horizontal table. a string, which joins these two masses, hangs over the edge supporting a pulley, which suspends a particle of mass 3m.the pulley has negligible mass. the two parts of the string on the table are parallel and perpendicular to the edge of the table. the hanging parts of the string are vertical. find the acceleration of the particle of mass 3m.

What sort of waves exhibit the doppler effect?

In addition to gravity, what is the other predominant force that affects the motion of a pendulum?