Answer: Option B
Distance of sound detector from walls
Tag Archives: sound
Testing for Gold
Light and sound wave diagram in different mediums with different density
Light and sound are both waves. So both carry energy from one place to another.
Light, which is part of the electromagnetic spectrum, is a transverse wave, It can travel through a vacuum at speed 3.0 x 108 m/s. As the light travels from an optically less dense medium (air) to an optically denser medium (liquid or glass), the light undergoes refraction and bends towards the normal due to a decrease in speed.
Light: Optically less dense medium to denser medium:
– speed decreases
– wavelength shorter
– frequency remains constant
Sound is a longitudinal wave. It requires a medium to pass through and it cannot pass through a vacuum. Opposite to light, as the sound travels from a less dense medium (air) into a denser medium (water or solid), the speed increases.
Sound: Less dense medium to denser medium:
– speed increases
– wavelength longer
– frequency remains constant
Refers to the image below to understand how the waves behave in different mediums.
Click here to revise on the calculation of refractive index for light
Different kind of sounds
Students tend to think that ultrasound is a totally different kind of wave, or it is part of the electromagnetic spectrum, which is wrong!
The different kind of waves below are just different kind of sounds. So the properties of sound apply to all. Ultrasound is also sound wave, just that the frequency is greater than 20 kHz which is outside the range of audible frequencies for us.
Watch “Knife Uses Ultrasonic Waves to Cut Through Virtually Anything with Ease” on YouTube
TODAYonline | YOU LIFT ME UP
Didn’t know ultrasound has such usage 😉
Time interval between two sounds from a gun – direct and reflected sound
Solutions: Option B
You can view the video tutorial here or the written solutions below.
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