With the vibrator turned off, the $120\,\text{g}$ metal block is moved vertically and let go. Fig. 4.2 shows how the displacement $y$ of the block from its equilibrium position changes with time $t$. For the block’s vibrations, calculate the angular frequency $\omega$.
For the block’s vibrations, calculate the energy of the vibrations.
The vibrator is now turned on. The vibration frequency is changed from $0.7f$ to $1.3f$, where $f$ is the block’s vibration frequency in (a). For the block, complete Fig. 4.3 to show how the amplitude of vibration varies with frequency. Label this line A.
Some light feathers are now added to the block in (b) so that air resistance increases. The vibration frequency is again varied from $0.7f$ to $1.3f$. The new amplitude of vibration is recorded for each frequency. On Fig. 4.3, draw a line to show how the amplitude of vibration varies with frequency. Label this line B.