I am completely stuck on this problem, and was wondering if anyone could point me in the right direction. 1. The problem statement, all variables and given/known data In the spinning fireworks display shown in the figure the ignited gun powder is ejected from the jets at a speed of 24.3 m/s. http://volta.byu.edu/ph121/homework/hw18f2.png [Broken] The jets are a distance of 0.462 m from the center of the fixture. If the total mass of gunpowder from all four jets is 250 g and the total mass of the jets themselves is 472 g, what will the angular velocity in radians per second of the fixture be when the gunpowder is exhausted? Neglect air resistance and assume that the mass of the arms of the fixture is inconsequential. Take the counter-clockwise direction (out of the page) as positive. 2. Relevant equations L = mvr L = I[tex]\omega[/tex] 3. The attempt at a solution Here is what I have tried thus far. I thought that I could simply calculate the Angular Momentum (L) by doing the following: L = 4*((mfuel/4 + mrocket/4) * v * r) 4*(.1805 * 24.3 * .462) = 8.105 then I simply subtracted the mass of the fuel for one rocket, and solved for v 8.105=4*(.118*v*.462) This apparently does not yield the correct answer. Any help would be greatly appreciated!