As measured from centre ice, a single wildly cheering hockey fan can produce a sound intensity level of 60dB. What sound intensity level would be produced by

20 000 cheering fans?

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If sound waves travel through the ground with an average speed of 6150 m/s and a powerful explosion occurs 5.00kn away, how much time will elapse between when you feel the vibration from the explosion and hear the explosion? Use v=344m/s for the speed of sound in air.

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You pick up two metal rods that look the same and appear to have the same mass. However, when you strike the first rod, it produces a sound that has a much higher frequency than the second rod. What does this result tell you about the speed of sound in the two rods?

THANKS.

To determine the sound intensity level produced by 20,000 cheering fans, we need to understand that sound intensity level is usually measured in decibels (dB) and follows the logarithmic scale. The formula to calculate sound intensity level (L) is:

L = 10 * log10(I / I0)

Where I is the intensity of the sound and I0 is the reference intensity level (usually taken as the threshold of human hearing, which is approximately 10^(-12) W/m^2).

In this case, we know that a single wildly cheering hockey fan produces a sound intensity level of 60 dB. To find the sound intensity level produced by 20,000 fans, we need to calculate the intensity and use the formula:

L = 10 * log10(20,000 * I_single / I0)

Since the intensity level is logarithmic, we can treat the 20,000 as a multiplier in the equation.

I_single = 10^(L_single/10) * I0

Substituting the given values:

I_single = 10^(60/10) * 10^(-12) W/m^2

Next, we can calculate the sound intensity level produced by 20,000 fans:

L = 10 * log10(20,000 * 10^(60/10) * 10^(-12) / I0)

Now we can solve for L.

L = 10 * log10(20,000 * 10^(6) * 10^(-12) / 10^(-12))

L = 10 * log10(20,000 * 10^(6))

L = 10 * log10(20,000,000,000)

L = 10 * 9.301

L = 93.01 dB

Therefore, the sound intensity level produced by 20,000 cheering fans is approximately 93.01 dB.

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To calculate the time between feeling the vibration and hearing an explosion, we need to understand the difference in speeds between sound traveling through the ground (6150 m/s) and through the air (344 m/s).

Assuming that vibration travels at the same speed as sound through the ground, we can use the formula:

Time = Distance / Speed

In this case, the distance is given as 5.00 km, which is equal to 5,000 meters. We need to convert this to meters and then calculate the time.

Time = 5000 meters / 6150 m/s

Time = 0.813 seconds

Therefore, approximately 0.813 seconds will elapse between feeling the vibration and hearing the explosion.

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When you strike the first metal rod and it produces a sound with a much higher frequency than the second rod, it indicates that the speed of sound is higher in the first rod compared to the second rod.

The frequency of a sound wave is directly related to the speed of sound, where higher frequency corresponds to higher speed. Since the sound produced by the first rod has a higher frequency, it implies that the speed of sound is higher in that rod compared to the second rod.

To find the sound intensity level produced by 20,000 cheering fans, we need to understand the concept of sound intensity and how it relates to the number of cheering fans.

Sound intensity is measured in decibels (dB) and is defined as the power or energy carried by a sound wave per unit area. The formula to calculate sound intensity level in decibels is:

L = 10 * log10(I/I0)

where L is the sound intensity level in decibels, I is the sound intensity, and I0 is the reference intensity.

In this case, we are given that a single fan produces a sound intensity level of 60 dB. Let's assume that I1 is the sound intensity produced by a single fan. Therefore, we can write:

60 dB = 10 * log10(I1/I0)

To find the sound intensity produced by 20,000 fans, we can use the concept of sound being proportional to the square root of the number of sources. So, the sound intensity produced by 20,000 fans (I2) would be:

I2 = I1 * √(20,000)

Now, using the formula for sound intensity level, we can find the sound intensity level produced by 20,000 cheering fans:

L2 = 10 * log10(I2/I0)

Therefore, the sound intensity level produced by 20,000 cheering fans can be calculated using the given values and the formulas mentioned above.