Four pendulums $A, B, C$ and $D$ are hung from the same elastic support as shown in the figure. $A$ and $C$ are of the same length,while $B$ is shorter than $A$ and $C$,and $D$ is longer than $A$. If $A$ is given a displacement,then at steady state:

If the amplitudes of a damped harmonic oscillator at times $t=0, t_1$ and $t_2$ are $A_0, A_1$ and $A_2$ respectively, then the amplitude of the oscillator at a time of $(t_1+t_2)$ is

The value of maximum possible amplitude in the case of forced oscillations when the driving frequency is close to the natural frequency is:

You are riding in an automobile of mass $3000\; kg$. Assuming that you are examining the oscillation characteristics of its suspension system. The suspension sags $15\; cm$ when the entire automobile is placed on it. Also,the amplitude of oscillation decreases by $50 \%$ during one complete oscillation. Estimate the values of
$(a)$ the spring constant $k$ and
$(b)$ the damping constant $b$ for the spring and shock absorber system of one wheel,assuming that each wheel supports $750 \;kg$.

The amplitude of a damped oscillator is known to decrease to $0.9$ times its original amplitude in $5 \,s$. Approximately, by how many times its original amplitude will it decrease after another $20 \,s$?

To understand resonance,describe the experiment of oscillations of five pendulums.