Let's address the questions one by one based on the image you provided.

Question 1: "De quel type d'onde s'agit-il ? Comment appelle-t-on L et H ? Donner leurs valeurs."

This problem shows a progressive mechanical wave on a string. It is a transverse wave, as the displacement of the string is perpendicular to the direction of wave propagation.

• L is the wavelength, which is the distance between two consecutive points that are in phase (for example, two consecutive peaks or troughs). From the graph, $L = 0.4 \, \text{m}$.

• H is the amplitude, which is the maximum displacement from the equilibrium position. In this case, $H = 2 \, \text{cm}$ or $0.02 \, \text{m}$.

Question 2: "Peut-on conclure quant au sens de propagation de l'onde à ce stade?"

To determine the direction of propagation, we can compare the wave's progression between time $t_1$ and $t_2 = t_1 + 0.3 \, \text{s}$.

• In Figure 1 ($t = t_1$), we see a specific phase of the wave.
• In Figure 2 ($t = t_2$), the wave appears to have shifted to the left compared to Figure 1.

Since the wave has moved to the left, this indicates that the wave is propagating in the negative x-direction.

Summary:

1. The wave is a progressive transverse wave.
2. $L$ (wavelength) = 0.4 m, $H$ (amplitude) = 2 cm (0.02 m).
3. The wave propagates in the negative x-direction.

Would you like more details on the physics of wave propagation or on how to analyze the graphs in more depth? Let me know if you have more questions!

Here are 5 questions to expand on this topic:

1. How does the speed of the wave relate to the wavelength and the time interval between the figures?
2. What is the formula to calculate the wave velocity in terms of wavelength and frequency?
3. How can we determine the frequency of the wave from the given information?
4. What happens to the wave propagation if the amplitude $H$ is doubled?
5. How does the medium’s tension affect the speed of wave propagation on a string?

Tip: Understanding wave motion involves not just the physical displacement but also the relationship between wavelength, frequency, and velocity.