(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

http://img14.imageshack.us/img14/5489/25765454.png [Broken]

A projectile is launched from a cliff above level ground. At launch the projectile is 35 meters above the base of the cliff and has a velocity of 50 meters per second at an angle 37° with the horizontal. Air resistance is negligible. Consider the following two cases and use g = 10m/s^{2}, sin37° = 0.60, and cos37° = 0.80.

(Case I includes parts a. b. and c., which I don't need help on so will skip.)

Case II: A small internal charge explodes at point B in the following diagram, causing the projectile to separate into two parts of masses 6kg and 10kg. The explosive force on each part is horizontal and in the plane of trajectory. The 6kg mass strikes the ground at point D, located 30 meters beyond point C, where the projectile would have landed had it not exploded. The 10kg mass strikes the ground at point E.

http://img194.imageshack.us/img194/2348/23075084.png [Broken]

d. Calculate the distance x from C to E.

2. Relevant equations

Assuming it is conservation of momentum,

KE[tex]_{i}[/tex] = KE[tex]_{f}[/tex]

KE = (1/2)mv^{2}

m1v1[tex]_{i}[/tex] + m2v2[tex]_{i}[/tex] = m1v1[tex]_{f}[/tex] + m2v2[tex]_{f}[/tex]

3. The attempt at a solution

In part a., I've calculated that the total time from launch to landing at point C is 7s. In b., that the distance R from launch to C is 280m. And in c., V[tex]_{A}[/tex] = 40m/s, V[tex]_{B}[/tex] = 50m/s, and V[tex]_{C}[/tex] = 56.6m/s. All of these parts just required simple kinematics and logic.

But for part d., I'm stuck. I tried conservation of energy, using the velocity at B and the given masses to try to find the velocities of each of the particles after the explosion, but doing this I somehow proved that both velocities remain 50m/s (I think this means that my calculation assumed the explosion did not cause the particles to separate). I'm not sure where to go.

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# Homework Help: Conservation of momentum problem (I think?)

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