Finding Initial Velocity to Solve Bowling Ball Speed Problem

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To solve the bowling ball speed problem, the initial velocity can be determined by first calculating the time it takes for the ball to hit the pins. Given that the total time from release to hearing the sound is 2.45 seconds and the speed of sound is 340 m/s, the time for the sound to travel back is approximately 0.049 seconds. Subtracting this from the total time gives 2.401 seconds for the ball to reach the pins. Using the formula for speed, the velocity of the ball is calculated as 16.5 m divided by 2.401 seconds, resulting in a speed of approximately 6.87 m/s. This approach correctly accounts for the constant speed of the ball and the time taken for sound to return.
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I've tried a few different equations but I'm not sure how to start this problem. I just realized I'm looking for the initial velocity since the speed of the ball is constant.

A bowling ball traveling with constant speed hits the pins at the end of a bowling lane 16.5 m long. The bowler hears the sound of the ball hitting the pins 2.45s after the ball is released from his hands. What is the speed of the ball?

Speed of sound=340 m/s
Bowling lane=16.5 m
Time till sound of ball heard=2.45s

This where I'm confused because I'm not sure which equations are the right ones to use.

Here is what I've attempted so far and I think I just realized its all wrong:

v=v(initial)+at
340 m/s=0+a(2.5s)
a=136m/s^2

(16.5m)/(2.45s)=6.73 s

I'm pretty sure this work is wrong but any help to start in the right direction would be much appreciated.
 
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The problem states that the ball is traveling at constant velocity so acceleration is not an issue. Knowing the speed of sound, figure out how long it took for the ball to hit the pins. Then knowing the time and distance of the lane you can find the velocity.
 
If speed of sound=340 m/s then (16.5m)/(340m/s)=0.049s. Subtract that from 2.45s and it took the ball 2.401s to reach the pins and then 0.049s for the sound to return back to the person. Correct?
 
Then the velocity=16.5m/2.401s which gives v=6.87 m/s
 
Looks good to me
 
The book claims the answer is that all the magnitudes are the same because "the gravitational force on the penguin is the same". I'm having trouble understanding this. I thought the buoyant force was equal to the weight of the fluid displaced. Weight depends on mass which depends on density. Therefore, due to the differing densities the buoyant force will be different in each case? Is this incorrect?

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