3.4 Sound
1. This question has 4 part(s).
1.1. The text describes the process by which scientists worked towards the current accepted value for the speed of sound.
Read the text then answer the questions relating to it.
Measuring the speed of sound in air
1 | After the wave nature of sound had been identified, many attempts were made to measure its speed in air. |
The earliest known attempt was made by the French scientist Gassendi in the 17th century. | |
Gassendi timed the interval between seeing the flash of a gun and hearing the bang from some distance away. | |
He assumed that, compared with the speed of sound, the speed of light is infinite. | |
5 | Gassendi concluded that the speed of sound was 480 m/s. |
A much better value of 350 m/s was obtained by the Italian physicists Borelli and Viviani using the same procedure. | |
In 1738 a value of 332 m/s was obtained by scientists in Paris. | |
This is remarkably close to the currently accepted value considering the measuring equipment available to the scientists at that time. | |
In 1740 another Italian, Bianconi, showed that sound travels faster when the temperature of the air is greater. | |
10 | Since 1986 the accepted value for the speed of sound has been 331.29 m/s at 0 °C. |
Explain why Gassendi needed to assume that ‘compared with the speed of sound, the speed of light is infinite’ (line 4).
1.2. Use Gassendi’s value for the speed of sound (line 5) to calculate the time between seeing the flash of a gun and hearing the sound if the observer was standing 2.5 km from the gun.
time = ____________________ s
1.3. The value obtained by Borelli and Viviani is described as being ‘much better’ than that obtained by Gassendi (line 6).
Explain why modern writers would judge this result as 'much better'.
1.4. The passage refers to Bianconi's discovery that the speed of sound in air depends on temperature (line 9).
The equation to find the speed of sound in dry air can be written
Where θ is the temperature in °C, and k is a constant.
Calculate a value for k using data from the passage. You do not need to give units for k.
Ai এর মাধ্যমে
১০ লক্ষ+ প্রশ্ন ডাটাবেজ
প্র্যাকটিস এর মাধ্যমে নিজেকে তৈরি করে ফেলো
উত্তর দিবে তোমার বই থেকে ও তোমার মত করে।
সারা দেশের শিক্ষার্থীদের মধ্যে নিজের অবস্থান যাচাই
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