Physics 9702 · AS & A Level · Simple harmonic oscillations
Simple harmonic oscillations — practice question
An oscillator makes a metal plate vibrate vertically, as illustrated in Fig. 2.1. A little sand is then sprinkled onto the plate. Fig. 2.2 shows how the sand’s acceleration, $a$, changes with displacement $y$.
(a(i))[2]
Use Fig. 2.2 to show how it can be inferred that the sand is in simple harmonic motion.
(a(ii))[2]
Calculate the frequency of oscillation of the sand.
(b)
The amplitude of oscillation of the plate is slowly raised above $8\,\text{mm}$. The frequency stays constant. At a certain amplitude, the sand is observed to lose contact with the plate.
(b(i))[1]
For the plate at the instant the sand first loses contact, state its position.
(b(ii))[3]
Calculate the amplitude of oscillation.
Worked solution & mark scheme
This 8-mark question has a full step-by-step worked solution and mark scheme. One marking point: “A line passing through the origin indicates acceleration $\propto$ displacement” …