Why Physics is difficult to understand from text and static pictures and how to overcome it

Physics is difficult to understand from static pictures and processed texts.

A typical picture on physics of waves, drawn by me for illustration purposes

For example, the picture hopes to illustrate the idea of a time-dependent phenomenon such as a longitudinal wave in a closed ends pipe. The picture shows only one instant of time say time t = T/2.

Missing Context

Adding the context will situate the physics described. Knowledge is constructed, the meaning is made, not transmitted from notes to the human mind. Without context, the mind has little ways to situate the meaning-making process. So stating that the physics described is about the longitudinal wave of sound in a closed ends pipe, showing a real-life pipe and later processing to a simulation helps in the bootstrapping process of knowledge building.

The diagram shows physics at one time when it is a time-varying phenomenon

I suggest using animation to depict the time-varying motion of the air particles.


YouTube version for the students to explore

a longitudinal wave in a closed ends pipe showing regions of compression ( high air pressure) and rarefaction (low air pressure)

Gif version for repeated animation to be inserted in electronic books or web pages.

The texts are processed or synthesized when understanding needs to be constructed

The text "The zero displacement occurs at both the rarefaction and the compression" is a summary derived after having observed the phenomena, it should not be presented as a fact to be summarized.

Text should be used to present the phenomena perhaps with specific time like at time = 0, time = T/4, time = 2T/4, time = 3T/4 and time = T where T is the period of the wave.

A suggested text could be like this

For example, in a closed ends pipe, the air particles are assumed to be ordered uniformly for ease of visualization. at time =0, the air particles are position in their undisturbed positions. The red line represents the displacement along the x-axis from the equilibrium position.
Assuming period of the wave is T.
At time = 0, at this point, the ends of the pipe are in the rarefaction and the middle pipe is in compression.
At time = T/4, the particles are all at their equilibrium position and therefore, no regions of rarefaction nor compression.
At time = T/2, the particles are distributed according to the red line, where at the ends, nodes N, the displacement is still zero away from the equilibrium. At this point, the ends of the pipe are in compression and the middle pipe is in rarefaction.
At time = 3T/4, the particles are all at their equilibrium position again and therefore, no regions of rarefaction nor compression
At time =T, the particles are back at the same position as T =0 and the cycle repeated.

Finally, add a simulation for students to inquiry and clarify their doubts and what if thinking. Inquiry learning is a signature learning strategy widely accepted by the Physics teaching community using both real and virtual laboratory.

Order of information is not intuitive

The displacement versus time graph should be above the pressure versus position graph as most students are more familiar with displacement after learning the topic on kinematics.

Consistently show Compression first then Rarefaction later. note that the "R" and "C" was shown probably because of the diagram positional order.