  "Q Zhang's Problem" is a teaching problem proposed by Qian Zhang, a science
teacher at Dongjiao Minxiang Primary School in Dongcheng District, Beijing. In
2022, she proposed that: (1) when explaining the knowledge points of frequency
in the "Sound" unit, experiments on the vibration of objects such as rubber
bands and steel rulers were used to assist students in learning, but the effect
was not obvious, because it was difficult for the naked eye to distinguish the
speed of vibration of objects such as rubber bands, and it was difficult to
correspond to the high and low frequencies; (2) Students seem to be confused
about the difference between frequency and amplitude. When guiding them to make
the rubber band vibrate faster, they tend to tug harder at the rubber band, but
this actually changes the amplitude rather than the frequency (changing the
frequency should be to control its vibrating chord length, similar to the
tuning method of a stringed instrument). Therefore, demonstration experiments
using objects such as rubber bands as frequencies do not seem suitable and
cannot effectively assist students in establishing the concept of frequency. We
hope to solicit opinions and solutions (research ideas) on this problem, with a
focus on two points: (1) the mathematical/physical explanation of the problem.
That is, does simply changing the amplitude really not affect the original
vibration frequency of the object (except when the amplitude is 0) (2)
explanation from a cognitive perspective: Why do people confuse the two
concepts? What is the cognitive mechanism behind it.
