| Date | May 2016 | Marks available | 2 | Reference code | 16M.3.HL.TZ0.11 |
| Level | Higher level | Paper | Paper 3 | Time zone | Time zone 0 |
| Command term | Describe | Question number | 11 | Adapted from | N/A |
Question
A solid sphere A suspended by a string from a fixed support forms a simple pendulum.
The Q factor for this system is 200 and the period of oscillation is approximately 0.4s.
The sphere A is displaced so that the system oscillates. Discuss, with reference to the Q factor, the subsequent motion of the pendulum.
The support point P of the pendulum is now made to oscillate horizontally with frequency f.
Describe the amplitude of A and phase of A relative to P when
(i) f = 2.5 Hz.
(ii) f = 1 Hz.
Markscheme
high Q means low damping OR system oscillates with low damping
«exponential» decrease of amplitude/energy OR oscillates about 200 times before coming to rest
loses about 3% of energy per cycle OR loses small amount of energy each cycle
(i) large amplitude/resonance
(ii) small amplitude AND A «almost» in phase with P
