
William W. answered 03/27/24
Experienced Tutor and Retired Engineer
The initial vector is 267m (where "m" is the mass of the rocket) with a direction straight up. So, after the explosion the sum of the three pieces must also have a sum of 267m in the y-direction. Since piece "1" moves to the right, it's y-direction component is zero. Piece 2 is moving only in the y-direction but since it's mass is only 1/3m, its momentum vector (in the y-direction) is (204)(1/3)m or 68m. Piece "3" must then have a y-component of 267m - 68m or 199m. Piece 3 had a mass of (1/3m) so:
(1/3m)(v) = 199m or v3-y = 597 m/s (y-direction component of the velocity of piece 3)
Since there was no x-component of the "before explosion" momentum, then the sum of the x-components after the explosion must be zero. Piece 1 was moving right at 344 but with a mass of 1/3m therefore its momentum (in the x-direction) was (344/3)m. That means piece 3 would have an x-component of (344/3)m to the left. Or the x-component of the velocity of piece 3 is 344 m/s left.
Use the Pythagorean Theorem to calculate the magnitude of the resultant velocity:
magnitude of v3 = √(5972 + 3442) = 689 m/s
Use inverse tangent to calculate the direction. Let θ be the angle above straight left:
θ = tan-1(597/344) = 60ˆ