Calculating Submarine Recoil Speed from Torpedo Launch

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To calculate the initial recoil speed of a submarine after firing a torpedo, the conservation of momentum principle is applied. The mass of the submarine is 2.3 million kg, and the torpedo has a mass of 260 kg with a speed of 100.9 m/s. The initial momentum is zero, leading to the equation Mtorpedo * Vtorpedo = Msub * Vsub. The calculated recoil speed of the submarine is approximately 0.0114 m/s, but the user suspects it might be incorrect due to the precision required by the online homework system. The discussion highlights the importance of significant figures in calculations.
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A submarine of mass 2.3 times 106 kg and initially at rest fires a torpedo of mass 260 kg. The torpedo has an initial speed of 100.9 m/s. What is the initial recoil speed of the submarine? Neglect the drag force of the water.

My work:

Pi=Pf
Pi=0
Pf= Mtorpedo * Vtorpedo - Msub * Vsub

Vsub = (260kg * (100.9 m/s) ) / 2.3 x 10^6

I get Vsub = .0114 m/s

Why is this wrong?? Thanks
 
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Looks OK to me. Why do you think it's wrong?
 
Stupid online homework system, I had to take the answer out a few more decimal places.

Thanks for your help Doc Al, appreciate it.
 

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