Question

An unstable nucleus with a mass of 18.0 ✕ 10-27 kg initially at rest disintegrates into three particles. One of the particles, of mass 4.1 ✕ 10-27 kg, moves along the positive y-axis with a speed of 8.0 ✕ 106 m/s. Another particle, of mass 7.7 ✕ 10-27 kg, moves along the positive x-axis with a speed of 4.0 ✕ 106 m/s. (Assume that mass is conserved.)
(a) Determine the third particle's speed.
(b) What is the direction of motion? (from the positive x-axis)

Answer 1

momentum is conserved. In the x direction, find out the x component of the third partical (using momentum)
then, in the y direction, find the component of the third partical.

Now, yuu have the x, y componets of momnetum of the third aprtical. Solve for speed, and direction.