$ = 4[\sin 3\omega \,t]$ (By using $\sin 3\theta = 3\sin \theta - 4{\sin ^3}\theta )$
$\therefore $ maximum acceleration ${A_{\max }} = {(3\omega )^2} \times 4 = 36{\omega ^2}$
| Column $I$ | Column $II$ |
| $(A)$ Potential energy of a simple pendulum (y axis) as a function of displacement ( $\mathrm{x}$ axis) | $Image$ |
| $(B)$ Displacement (y axis) as a function of time (x axis) for a one dimensional motion at zero or constant acceleration when the body is moving along the positive $\mathrm{x}$-direction | $Image$ |
| $(C)$ Range of a projectile (y axis) as a function of its velocity ( $\mathrm{x}$ axis) when projected at a fixed angle | $Image$ |
| $(D)$ The square of the time period (y axis) of a simple pendulum as a function of its length ( $\mathrm{x}$ axis) | $Image$ |


$1.$ The phase space diagram for a ball thrown vertically up from ground is
mcq $Image$
$2.$ The phase space diagram for simple harmonic motion is a circle centered at the origin. In the figure, the two circles represent the same oscillator but for different initial conditions, and $E_1$ and $E_2$ are the total mechanical energies respectively. Then $Image$
$(A)$ $ E_1=\sqrt{2} E_2$ $(B)$ $ E_1=2 E_2$
$(C)$ $ E_1=4 E_2$ $(D)$ $ E_1=16 E_2$
$3.$ Consider the spring-mass system, with the mass submerged in water, as shown in the figure. The phase space diagram for one cycle of this system is $Image$
mcq $Image$
Give the answer question $1,2$ and $3.$
($A$) The amplitude of oscillation in the first case changes by a factor of $\sqrt{\frac{M}{m+M}}$, whereas in the second case it remains unchanged
($B$) The final time period of oscillation in both the cases is same
($C$) The total energy decreases in both the cases
($D$) The instantaneous speed at $x_0$ of the combined masses decreases in both the cases