Pelican Dive: Calculating Escape Height for Fish

In summary, to find the minimum height a pelican must start its dive from to allow a fish to escape, one must use the equation change in X=Vot+.5At^2 and solve for time. Then, subtract the time it takes for the fish to evade (0.15 seconds) and plug the new time back into the equation to find the distance from the fish the pelican can be with the fish still being safe. In this scenario, the minimum height is approximately 2.8875 meters.
  • #1
homeworkboy
35
0
Pelicans tuck their wings and free-fall straight down when diving for fish. Suppose a pelican starts its dive from a height of 20.0 m and cannot change its path once committed.If it takes a fish 0.15 s to perform evasive action, at what minimum height must it spot the pelican to escape? Assume the fish is at the surface of the water.
 
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  • #2
bump please help
 
  • #3
Homeworkboy,
I am a bit rusty with these types of problems, but i believe that i have it.

Where you would start, is to find out how long it would take the pelican to get to the water, regardless of fish.

change in X=20m
acceleration=freefall, or 10m/s2 (its 9.8 to be exact, but im' just using 10)
time=?
starting Velocity=0

so change in X=Vot+.5At2

so, you get the time it takes the pelican to reach the water by solving that. Now since the fish can evade in .15 seconds, take the time yu found in the previous problem and subtract .15 from it. This will give you the time that it takes for the pelican to get to .15 seconds away.

Now that you have the time it takes for the pelican to get within evading distance, plug THIS time back into the change in position equation to get the distance from the fish the pelican can be with the fish still being safe.

I would like you to go back through and do the steps, but to check your answer, the answer that i ended up with is 2.8875m.

Good luck in physics!
 
  • #4
Hey thanks a million! i perfectly understood it...i worked it out the way u said and it came upto 2.86 (since i used 9.8m/s2)...so i checked it and it was the right answer..thanks alot..
 

Related to Pelican Dive: Calculating Escape Height for Fish

1. How does the Pelican Dive method work?

The Pelican Dive method uses mathematical calculations to determine the escape height of a fish from a pelican's beak. This is based on the maximum velocity that the pelican can reach while diving and the weight and size of the fish.

2. Why is calculating escape height important for fish?

Calculating escape height is important for fish because it gives them a better chance of avoiding predation by pelicans. By understanding the maximum height that a pelican can reach while diving, fish can better assess the risk of being caught and can potentially adjust their behavior to increase their chances of survival.

3. What factors are considered in the Pelican Dive method?

The Pelican Dive method takes into consideration the weight and size of the fish, the maximum velocity of a pelican's dive, and the height of the water column. These factors are used to calculate the required escape height for the fish to avoid being caught by a pelican.

4. Can the Pelican Dive method be applied to all types of fish?

Yes, the Pelican Dive method can be applied to all types of fish as long as the necessary data is available. However, the results may vary depending on the species and their behavior, so it is important to consider the specific characteristics of the fish being studied.

5. How accurate is the Pelican Dive method?

The accuracy of the Pelican Dive method depends on the accuracy of the data used in the calculations. If the weight, size, and diving velocity of the pelican are accurately measured, the results can be quite accurate. However, there may be other factors that can affect the escape height of fish, such as water current and visibility, which may not be accounted for in the calculations.

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