triple products

? Particle 1 is moving at velocity v1i and particle 2 is at rest
? In the x-direction, the initial momentum is m1v1i
? In the y-direction, the initial momentum is 0
? After the collision, the momentum in the x-direction is m1v1f cos q + m2v2f cos f
? After the collision, the momentum in the y-direction is m1v1f sin q - m2v2f sin f



Position and particle
The position of a particle on an x-axis located the particle with respect to the origin , or zero point , of the axis . the position is either positive or negative , according to which side of the origin the particle is on , or zero if the particle is at the origin.
The positive direction on an axis is the direction of increasing positive number s , the opposite direction is the negative direction. The moving object is either a particle (by which we mean a point – like object such as electron) or an object that moves like a particle such that every portion moves in the same direction and at the same rate.). in our study , we describe the moving object as a particle regardless of its size.