The displacement of a particle in SHM is given by $3 \sin 314 \mathrm{t}+4\cos 314\mathrm{t}$. Amplitude and the frequency of the motion are

Two SHM is represented by ${\mathrm{y}}_1=0.1 \sin \left[100\mathrm{\pi t}+\frac{\mathrm{\pi }}{3 }\right] \mathrm{and} {\mathrm{y}}_2=0.1 \cos \mathrm{\pi t}$. The phase difference of the velocity of particle $1$ with respect to $2$ is

A particle moves such that its acceleration $\mathrm{a}$ is given by $\mathrm{a}= -\mathrm{bx}$, where $\mathrm{x}$ is the displacement from equilibrium position and $\mathrm{b}$ is a constant. The period of oscillation is

The displacement of an object attached to a spring and executing simple harmonic motion is given by $x=\left(2\times {10}^{-2}\cos \pi t\right) \mathrm{m}$. The time at which the maximum speed first occurs is$:$