The speed that a tsunami can travel is modeled by the equation [tex]S = 356 \sqrt{d}[/tex], where [tex]S[/tex] is the speed in kilometers per hour and [tex]d[/tex] is the average depth of the water in kilometers.

What is the approximate depth of water for a tsunami traveling at 200 kilometers per hour?

A. 0.32 km
B. 0.75 km
C. 1.12 km
D. 3.17 km



Answer :

To solve this problem, we want to determine the depth of water [tex]\( d \)[/tex] that corresponds to a tsunami traveling at a speed of [tex]\( S = 200 \)[/tex] kilometers per hour using the given formula:

[tex]\[ S = 356 \sqrt{d} \][/tex]

We will evaluate each given depth and see which one provides a speed closest to 200 kilometers per hour.

1. Depth = 0.32 kilometers

Let's compute the speed:

[tex]\[ S = 356 \sqrt{0.32} \][/tex]

Simplifying, we get:

[tex]\[ S \approx 356 \times 0.5657 \approx 201.38 \text{ km/h} \][/tex]

This is quite close to 200 km/h.

2. Depth = 0.75 kilometers

Let's compute the speed:

[tex]\[ S = 356 \sqrt{0.75} \][/tex]

Simplifying, we get:

[tex]\[ S \approx 356 \times 0.866 \approx 308.31 \text{ km/h} \][/tex]

This speed is significantly higher than 200 km/h.

3. Depth = 1.12 kilometers

Let's compute the speed:

[tex]\[ S = 356 \sqrt{1.12} \][/tex]

Simplifying, we get:

[tex]\[ S \approx 356 \times 1.058 \approx 376.75 \text{ km/h} \][/tex]

This speed is also higher than 200 km/h.

4. Depth = 3.17 kilometers

Let's compute the speed:

[tex]\[ S = 356 \sqrt{3.17} \][/tex]

Simplifying, we get:

[tex]\[ S \approx 356 \times 1.78 \approx 633.84 \text{ km/h} \][/tex]

This speed is much higher than 200 km/h.

Comparing all these speeds, the depth that gives a speed closest to 200 km/h is:

Depth = 0.32 kilometers, which corresponds to a speed of approximately 201.38 km/h.

Therefore, the approximate depth of water for a tsunami traveling at 200 kilometers per hour is 0.32 kilometers.