MATERI FISIKA TENTANG GELOMBANG KELAS 11

Summary

In this educational video, the speaker explains the fundamentals of waves, including the difference between transversal and longitudinal waves. The concepts of wavelength, amplitude, frequency, and period are covered, along with practical examples and formulas. The speaker illustrates how to calculate wave speed using the relationship between frequency and wavelength, providing real-life problem-solving applications. The video also walks through example questions, making it easier for viewers to understand wave behavior and its calculations. Overall, the content serves as a solid introduction to wave theory and its practical applications.

Takeaways

• 😀 Gelombang (wave) refers to a vibration that propagates through a medium.
• 😀 There are two main types of waves: transversal and longitudinal.
• 😀 In a transversal wave, the direction of vibration is perpendicular to the direction of wave propagation.
• 😀 In a longitudinal wave, the direction of vibration is parallel to the direction of wave propagation.
• 😀 A single wave cycle, or 'one wave', can be measured as the distance from one crest to another, or from one trough to another.
• 😀 The wavelength (λ) is the distance between one peak and the next, or between one trough and the next in both transversal and longitudinal waves.
• 😀 The amplitude of a wave is related to its maximum displacement from the equilibrium point.
• 😀 The frequency (f) refers to the number of oscillations or cycles per unit of time, while the period (T) is the time taken for one complete wave cycle.
• 😀 The formula for wave velocity (v) is derived from the equation v = f × λ (frequency × wavelength).
• 😀 An example calculation showed that with a frequency of 175 Hz and a wavelength of 3 meters, the wave speed was calculated to be 525 m/s.
• 😀 In another example, a wave with a period of 1/50 seconds and a wavelength of 1.6 meters was used to calculate the wave speed, resulting in a value of 80 m/s.

Q & A

What are the two types of waves explained in the script?

The two types of waves explained are transversal waves and longitudinal waves. In transversal waves, the particle motion is perpendicular to the direction of wave propagation, while in longitudinal waves, the particle motion is parallel to the direction of wave propagation.

What is the key difference between transversal and longitudinal waves?

The key difference is that in transversal waves, the direction of particle motion is vertical (up and down), while in longitudinal waves, the particle motion is horizontal (compressing and expanding along the direction of the wave).

How is the wavelength defined in transversal waves?

In transversal waves, the wavelength is the distance between two consecutive peaks (or troughs) of the wave. It can be measured from one peak to the next or from one trough to the next.

How is the wavelength defined in longitudinal waves?

In longitudinal waves, the wavelength is the distance between two consecutive compressions (rapatan) or rarefactions (renggang), or between similar points in the wave cycle.

What is the formula to calculate the speed of a wave?

The formula to calculate the speed of a wave is: v = f * λ, where 'v' is the wave speed, 'f' is the frequency, and 'λ' is the wavelength.

What is the relationship between frequency and period?

The frequency (f) is the number of wave cycles per unit of time, while the period (T) is the time it takes to complete one cycle. The relationship is: T = 1/f, meaning period is the inverse of frequency.

What does the symbol λ represent in wave equations?

The symbol λ represents the wavelength in wave equations, which is the distance between two consecutive peaks or troughs in a transversal wave, or between compressions or rarefactions in a longitudinal wave.

What would be the speed of a wave if the frequency is 175 Hz and the wavelength is 3 meters?

Using the formula v = f * λ, the speed of the wave would be: v = 175 Hz * 3 m = 525 m/s.

How do you calculate the frequency of a wave given its period?

The frequency can be calculated by taking the reciprocal of the period. If the period is T, then frequency f = 1/T.

Given a period of 1/50 seconds and a wavelength of 1.6 meters, how do you calculate the speed of the wave?

First, calculate the frequency using f = 1/T. If T = 1/50, then f = 50 Hz. Now, use the formula v = f * λ. With f = 50 Hz and λ = 1.6 meters, the speed v = 50 * 1.6 = 80 m/s.