Science Buddies: "Ask an Expert"

Help!
My daughter is doing a science fair project on tsunamis: study the effect of water depth on wave velocity. All the steps and analyzing our data are done. However, at the very end of the Science Buddies project, it wants an additional calculated result to show similar shaped curves on a graph compared to the results we experimented with. The equation is V=sqrt(gd)
V=velocity in meters/second (m/s)
g=acceleration of gravity (9.8 meters/second squared)
d=water depth in meters

How do I solve this equation? What numbers am I plugging in? This is in meters, where our project is in cm (obviously due to size).

This equation states that velocity is the square root of the product of the acceleration of gravity and water depth.

[Administrator note: Project: https://www.sciencebuddies.org/science- ... e-velocity ]

Hi - In the formula, you are solving for V (velocity) by using the Water Depth (d) from your experiment and acceleration of gravity (g, which is given). So at each water depth, what is the velocity when you use the formula? (That is what you are calculating.)

To use the formula, you can convert your water depth values from centimeters to meters by dividing by 100. For example, 10 centimeters is 10/100 = 0.1 meters.

Note: The formatting on the formula in the procedure needs to be updated to make it clearer. You are taking the square root of the product of g and d. (Just mentioning this so that it is clear that both g and d are intended to be inside the square root symbol.)

After finding out V for each of your water depth values, you plot those values on a graph and see how they compare to the wave velocity you got when conducting the experiment in the tank. (In Step 5 of the Analyzing Data section, you made a graph of wave velocity at each water depth.) (Note: You'll need to convert your wave velocity values to m as well to compare.)

I hope this helps.

Amy
Science Buddies

Thank you so much for your response. It was very helpful and we are on the home run to finishing the science fair project. We enjoyed this very much. We found our average of the velocity to the water depth. We found that it deemed true to the mathematical equation in meters with the formula given. We were able to create two plot graphs for each test: 1) the science experiment and 2) the calculations for meters in a hypothetical tsunami scenario in meters.