Some AP Phys problem help

<p>So, for students with Giancoli, it might help that I tell you I'll be describing problem 34 in chapter 7 (6th edition).</p>

<p>An explosion breaks an object into two pieces, one of which has 1.5 times the mass of the other. If 7500 J were released in the explosion, how much kinetic energy did each piece acquire?</p>

<p>Right now I've tried the Work-Energy theorem and came up with "7500J = KE(f)-KE(i), where KE(i) is 0 and there is no dPE. </p>

<p>KE(f) can be written as "1/2mv(1)'^2 + 1/2(3/2)mv(2)'^2"</p>

<p>=> 7500J = 1/2mv(1)'^2 + 3/4mv(2)'^2</p>

<p>Given that this is an inelastic "collision" (explosion), Momentum is conserved.</p>

<p>So P(i) = P(f), but P(i) = 0.</p>

<p>=> 0 = mv(1)' + 3/2mv(2)'</p>

<p>==> -mv(1)' = 3/2mv(2)' , the "m"s cancel</p>

<p>===> -2/3v(1)' = v(2)'.</p>

<p>So I got this relationship and plugged it back into the Work-Energy Thm., but I'm not really getting the right answer.</p>

<p>Anybody have any suggestions?</p>

<p>Fear not O my brothers! I have figured it out.</p>

<p>What were you doing wrong?</p>