Finding the Velocity of the Third Piece after an Explosion

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An object with a total mass of 15.6 kg explodes into three pieces, with two pieces having known masses and velocities. The first piece has a mass of 5 kg and moves at 27.6 m/s at a 21° angle, while the second piece has a mass of 5.5 kg moving at 20.2 m/s at a 26° angle. The third piece's mass is determined to be 5.1 kg, and the user attempts to calculate its velocity components using conservation of momentum. Initial calculations for the x and y components of the third piece's velocity were incorrect, leading to confusion over the angles and vector directions. Ultimately, the user resolved the issue independently and no longer requires assistance.
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Homework Statement


Hello, this is my first time posting. I'd appreciate any help.
An object with total mass mtotal = 15.6 kg is sitting at rest when it explodes into three pieces. One piece with mass m1 = 5 kg moves up and to the left at an angle of θ1 = 21° above the –x axis with a speed of v1 = 27.6 m/s. A second piece with mass m2 = 5.5 kg moves down and to the right an angle of θ2 = 26° to the right of the -y axis at a speed of v2 = 20.2 m/s.
http://smartphysics.com/images/content/mechanics/ch13/explosion3.png

What is the x-component and y-component of the velocity of the third piece?
What is the magnitude of the velocity of the center of mass of the pieces after the collision?

Homework Equations


P = M*V
conservation of momentum

The Attempt at a Solution



I already found the third mass to equal 5.1kg. Then how I tried finding x and y is kind of lengthy and I don't know if it makes sense, but I'll try to explain.
I started out with: M(final)V(final) = m1v1 + m2v2 + m3v3
And then I plugged in what I had. Since it started at rest, I know the left side is equal to zero. Then I tried plugging in what I had, but it's where I started to get confused because of the angles.
0 = 5*27.6*Vector1 + 5.5*20.2*Vector2 + 5.1*V3*Vector3
5.1*V3*Vector3 = -5*27.6*Vector1 + -5.5*20.2*Vector2
Then I flipped the directions the vectors on the left side of the equation were going to make them positive and set up triangles.
For the first mass I have a triangle with a 21degree angle and solved for the other sides, I knew the hyp would just be m1*v1,
hyp = 138, opp = 49.45, adj = 128.83
And I did the same for the second mass
hyp = 111.1, opp = 99.856, adj = 48.703
Then I added the x-direction together
49.45 + -99.856 = -50.406
and y direction
-128.83 + 48.703 = -80.127
And then I set up another triangle and use Pythagorean theorem to find the hyp
which i got to be 113.51. Then to find the angle I used tan-1(80.127/50.406) and multiplied that by the 113.51 and got 1.24.

My x and y are wrong. And I know it's way too high for velocity, so I also tried divided by the mass, but it's still wrong. I was wondering if I'm anywhere close and where I went wrong. Thank you.
 
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I found it out. Nevermind.
 
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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