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Three Piece explosion

A firecracker in a coconut blows the coconut into three pieces. Two pieces of equal mass fly off south and west, perpendicular to each other, at 20 m/s. The third piece has twice the mass as the other two.What is the speed of the third piece?

really boggled, no masses are given? i thought since the mass is double then the speed would be half of the speed of the 1st and 2nd pieces? anyone have an equation to help me out?


Resolve the momentums in the X and Y directions assuming the body is initially at rest:

[tex]\sum m_i v_i = 0[/tex] Here's the X direction (assuming east/west are the postive/negative x axis):

[tex] -20m + 2mv_x = 0[/tex]

and in the Y direction:

[tex] -20m + 2mv_y = 0[/tex]

It's easy to see what [tex]v_x[/tex] and [tex]v_y[/tex] are.
still dont understand, what do i put for the masses?
It doesn't matter what the masses are. The ratios are given. The masses will cancel out later once you have the relationship worked out.
so Vx = 10 and Vy = 10? after i solved in the equations

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