21.Two particles executing SHM have time periods in ratio of 1:4. Both are given small displacements in the same direction at the same instant. They will again be in phase at the mean position after the second particle has completed n oscillations. The value of n is:

22.A particle of mass 10 kg is executing SHM of time period 2 s and amplitude 0.25 m. The magnitude of maximum force on the particle is:

23.In a simple harmonic oscillator, at the mean position:

24.The total energy of a particle executing SHM is proportional to:

25.A body executing SHM has its velocity 10 cm/s and 7 cm/s, when its displacements from the mean position are 3 cm and 4 cm respectively. The length of path is: