Science Do as directed; [1 M ]

No, transverse waves cannot travel in glasses.

Transverse, because the vibration of particles of the spring are at right angles to the direction of wave propagation.

Yes, sound can travel through iron and as well as water.

Transverse, because the light waves are electromagnetic waves in which electric and magnetic fields oscillate in the direction at right angles to each other and also to the direction of propagation of the wave.

Supersonic speed refers to the speed of an object which is greater than the speed of sound.

The three tiny bones present in the middle part of ear are: anvil, hammer and stirrup.

Longitudinal, because the direction of vibration of air molecules is to and fro about its mean position along the direction of propagation of wave due to the vibration of quartz crystal.

As the frequency increases the pitch of the sound also increases.

When the school bell vibrates, it forces the adjacent particles in air to vibrate. This disturbance gives rise to a wave and when the bell moves forward, it pushes the air in front of it. This creates a region of high pressures known as compression. When the bell moves backwards, it creates a region of low pressure know as rarefaction. As the bell continues to move forward and backward, it produces a series of compressions and rarefactions. This makes the sound of a bell propagate through air.

• Slowest - Sound
• Fastest - light

Ultrasound scans are used to monitor the growth of developing baby in the uterus of the mother.

The persistence or sound in a big hall or auditorium is called reverberation.

An object should vibrate in order to produce sound.

Stirrup.

Soundboard is a concave board which is kept behind the speaker on the stage of a big hall.

1. Megaphone and bulb horn.
2. Stethoscope.
3. Soundboard.

• Solid - table.
• Liquid - water.
• Gas - air.

Ear canal.

Combination of transverse and longitudinal.

Transverse and Longitudinal waves.

Tuning fork is used to produce sound in laboratory experiments.

Sound waves in air: Longitudinal, Compression, Rarefaction.
Water waves: Transverse, Crest, Trough.

Supersonic is used to denote a speed greater than the speed of sound.

Eustachian tube.

Sound is produced by vibration. When a body vibrates, it forces the neighbouring particles of the medium to vibrate. This creates a disturbance in the medium, which travels in the form of waves. This disturbance, when reaches the ear, produces sound.

Loudness of the sound is measured in decible and ac loudness depends on amplitude it also depends on amplitude of the sound.

Sound travels slowest in gases.

Ultrasonic sounds.

Wavelength, frequency and speed of the sound waves remain the same.

The function of three tiny bones in the ear is to increase the strength of vibrations coming from the ear drum before passing them onto the inner ear.

Vocal cords vibrate in our voice box when we talk.

1. Loudness.
2. Pitch.
3. Timbre.

No, sound cannot travel through vacuum.

Bat navigates and finds its food by echolocation.

It is common observation that in the rainy season, the flash of lightning is seen first and the sound of thunder is heard a little later. That’s because, speed of light is very high as compared to speed of sound in air.

Pitch helps us to distinguish between a man’s voice and a woman’s voice, even without seeing them.

Curtains and carpets can make our big room less echoey.

Transverse waves.

SI unit of frequency is hertz.

Transverse wave.

Auditory nerve.