A firecracker is tossed straight up into the air. It explodes into three pieces of equal mass just as it reaches the highest point. Two pieces move off at 120 m/s at right angles to each other. How fast is the third piece moving?
2007-10-14 13:46:28 · 1 answers · asked by Jerry M 1 in Science & Mathematics ➔ Physics
Since it explodes at its highest point and it was thrown straight up, it has zero velocity when it explodes. And zero momentum when it explodes.
Sum of momentum before = Sum of momentum after
From symmetry you can probably see what direction the 3rd piece goes. Define that as one axis. I would choose that it is the neg X axis. Then break the momentum of the 1st and 2nd piece into +X and +/-Y axes. Their +/-Y components will cancel -- you see that?
Then the sum of the +X axis momentum for pieces 1 and 2 need to be equal and opposite the momentum of the 3rd.
2007-10-14 15:01:04 · answer #1 · answered by sojsail 7 · 0⤊ 0⤋