Projectile Motion Archery Problem

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The discussion revolves around solving a projectile motion problem related to archery, where an arrow is shot parallel to the ground and lands 61 meters away at a 3-degree angle. The participant initially used incorrect assumptions about the height and time calculations, leading to an incorrect velocity of 75.52 m/s instead of the expected 107 m/s. Key equations for projectile motion were mentioned, including those for vertical and horizontal motion. The correct approach involves recognizing that the angle relates to the final vertical velocity components rather than displacement. Clarification was provided that the horizontal velocity should be calculated using the relationship between horizontal distance and the angle.
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Hey guys, i realize this question has been asked on these forums before, and i have seen those posts, but they don't make sense to me, and this question is on my test tomorrow so i really need to figure it out.

Homework Statement



You are watching an archery tournament when you start wondering how fast an arrow is shot from the bow. Remembering your physics, you ask one of the archers to shoot an arrow parallel to the ground. You find the arrow stuck in the ground 61.0 m away, making a 3.00 degree angle with the ground.

So distance in the x direction is going to be 61m
and you have an angle theta that is 3 degrees

Homework Equations



v_f = V_i + at [eq1]
61tan3 = height that the arrow was initially fired from (i think this is where I am wrong)
d = V_i * t + 0.5at^2 [eq2]
Y_f = Y_i + V_iy * t + 0.5 * a_y * t^2 [eq3]
distance = speed*time [eq4]

The Attempt at a Solution



so i got that 61tan3 = 3.197
I used this value in [eq3] as my y_i so i got
0 = 3.197 + 0 + 0.5(-9.8)t^2 and i solved for t which ended up being 0.8077s
then i plugged my time into [eq4] like so 61 = 0.877 * V and got 75.52 m/s for my velocity. But the answer to this problem is 107. What am i doing wrong?
 
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The angle is formed by the horizontal and final vertical velocity components not the displacement components.

V_f = V_h tan 3

Where I use V_h for the constant horizontal velocity you wish to find.

You'll need to use eq1 and eq4.

That should be a big enough hint I hope.
 
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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