# If the speed of sound is 330 m/s. How high is the cliff?

• galeontiger
In summary, dropping a rock from a cliff produces a sound that is heard 3 seconds later. The height of the cliff doesn't affect the time it takes for the sound to reach the person, and the sound travels at 330 meters per second.

#### galeontiger

Hello, I tried solving this but to no avail.
Maybe someone could help me figure out the answer, thanks.

A rock is dropped from a sea cliff and the sound is heard striking the ocean 3.0s later. If the speed of sound is 330 m/s. How high is the cliff?

Thanks.

I know that the time it takes the rock to fall to the bottom and the time it takes for the sound to travel back up to the person takes a total of 3s.

I tried using the d=v1t + 1/2at^2 formula but that didn't work either.

I've thought of and tried to use most formulas, but I don't know how to do this problem. Please help me.

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What have you tried so far? You need to show some work, and if this is homework it really belongs in the homework forum.

Just remember that the time taken for the sound to reach your ears = 3 - the time taken for the rock to hit the water, and solve simultaneously.

@hage: How is my answer wrong?

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Saplingg, I'll send you a PM.

Hmmmm... I wonder if the problem is expressed incorrectly or if a teacher is just trying to make a point. Since you only have 2 significant digits for the time, the amount of time it takes makes no significant difference. In fact, using 3.00s for the time, and 9.81m/s^2, as well as 330m/s for the speed of sound, it still results in the same answer after rounding to three significant digits.

I think if you drop the rock, you can assume that 3 second is the time the rock reaches the sea plus the time is needed for the sound to reach your ear so if we consider h as the height
3= h/330+t
and for t we have: h=1/2gt^2
if we replace the t in the first equation from the second one
we can solve it!
is it ok?

## 1. How is the speed of sound related to the height of a cliff?

The speed of sound is not directly related to the height of a cliff. However, it can be used to calculate the height of a cliff if other variables, such as time, are known.

## 2. What is the formula for calculating the height of a cliff using the speed of sound?

The formula for calculating the height of a cliff using the speed of sound is: height = (speed of sound * time) / 2. This formula assumes that the sound wave travels straight down and back up, and that there is no wind or other factors affecting the speed of sound.

## 3. How accurate is the calculation of a cliff's height using the speed of sound?

The accuracy of the calculation depends on several factors, such as the accuracy of the speed of sound measurement, the precision of the timing, and the assumption that the sound wave travels straight down and back up. In ideal conditions, the calculation can be fairly accurate, but in real-world scenarios, there may be some margin of error.

## 4. Does the speed of sound change at different altitudes or temperatures?

Yes, the speed of sound does change at different altitudes and temperatures. Generally, the higher the altitude, the lower the air density, which results in a lower speed of sound. Similarly, as temperature increases, the speed of sound also increases. This can affect the accuracy of the calculation of a cliff's height using the speed of sound.

## 5. Are there any other methods for measuring the height of a cliff besides using the speed of sound?

Yes, there are other methods for measuring the height of a cliff, such as using trigonometry and measuring angles and distances. This method may be more accurate, but it also requires more equipment and expertise. Another method is using satellite imagery or LiDAR technology to measure the height of the cliff from a distance.