What causes waves to slow down: change in wave’s wavelength or change in its frequency and y?
The Correct Answer and Explanation is:
Waves can slow down due to a change in their wavelength or frequency, depending on the medium they are traveling through. However, the most common factor responsible for the change in wave speed is the change in wavelength, which is usually influenced by the properties of the medium, such as its density or elasticity.
Correct Answer: Change in Wavelength
Explanation:
The speed of a wave (v) is related to its frequency (f) and wavelength (λ) by the equation:
[
v = f \times \lambda
]
Where:
- ( v ) is the speed of the wave,
- ( f ) is the frequency of the wave,
- ( \lambda ) is the wavelength of the wave.
For waves traveling through different media (for example, from air to water), the speed can change, but typically the frequency of the wave remains constant because it is determined by the source of the wave. The change in speed primarily comes from the wavelength adjusting to the properties of the new medium.
When a wave enters a medium where the speed of propagation is different (such as from air to water), the wavelength changes. If the wave slows down in the new medium, the wavelength decreases, while the frequency remains the same. For instance, sound waves travel slower in denser media like water compared to air, causing the wavelength to shorten, but the frequency does not change unless the source is altered.
On the other hand, if the frequency of the wave is changed (for instance, by altering the vibration rate of the source), both the wavelength and the speed can change. However, in most practical scenarios, it is the medium that most strongly influences the wave speed, and the primary adjustment is in wavelength.
Therefore, a change in wavelength is the primary factor in a wave slowing down. The frequency often remains constant in the transition between media, while the wavelength adapts to match the new wave speed.