NATIONAL ACADEMY FOR LEARNING
GR 7- PHYSICS REVISION WORKSHEET
Fill in the blanks with the words given below.
1. Describe how sound is transmitted.
2. Sound is a form of ______________ that is transferred from one point to another by
the ______________ of particles. As sound is a ___________ wave, the direction of
________________of the particles is parallel to the direction of propagation of the
wave.
3. As sound is propagated by the vibration of particles, sound requires a medium to
travel. Unlike light, sound cannot travel in ______________.
4. The speed of sound is dependent on the medium it travels in. The __________ the
atoms in the medium, the faster the sound.
5. Speed of sound in air is ___________ m/s while speed of sound in water is
approximately ___________ m/s. As the particles in a metal are very _________, the
speed of sound in metals is approximately ______________.
6. _____________is the number of complete waves or vibrations that go past a
particular point each second. The pitch of a sound depends on the frequency of
the vibrations that cause it. If there are _________of vibrations per ____________,
the frequency is _____________ and the sound has a high pitch, which is like a
___________ talking. If there are fewer (less) vibrations per second, the frequency
is _________________ and the sound has a low pitch.
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6a. Redraw the sound wave below with double the amplitude and twice frequency.
b. How will these changes affect the sound you hear?
___________________________________________________________________________
c. How many full waves are shown on the oscilloscope screen above.
_____________________________________________________________________________
7. Define the term echo.
_____________________________________________________________________________
8. State one use of ultrasound.
________________________________________________________________________________
9. What is the pitch of a sound wave related to?
________________________________________________________________________________
10. What is the loudness of a sound wave related to?
________________________________________________________________________________
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11. A ship’s echo sounder transmits a pulse of sound. It is then reflected back to the ship
by a shoal of fish to a receiver 0.2 s later. If the shoal of fish is 120 cm below the ship,
what is the speed of the sound in water?
12. Which wave diagram has both wavelength (k) and amplitude (A) labelled
correctly?
13. An electric guitar is generating a sound of constant frequency. An increase in which
sound wave characteristic would result in an increase in loudness?
14. In which type of wave is the disturbance parallel to the direction of wave travel?
If the frequency of a sound wave in the air remains constant, its energy can be varied
by changing its.
15. Which form(s) of energy can be transmitted through a vacuum?
16. When an object vibrates it creates a sound wave. How quickly the object vibrates
changes the sound.
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a. How is the vibration-creating trace A different from the vibration-creating
trace B? How can you tell from the traces?
b. How is the vibration causing the loud trace different from the vibration causing
the quiet trace?
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