An apparatus has been developed that enables one to investigate the conservation of a linear momentum in a two-dimensional collision experiment. It was found that a cycloidal slide yields a constant rolling time of the ball, independent of the release position on the slide. The two balls, released on two slides of the same size at any desired angle, produce a two-dimensional collision. The initial velocity of the ball before the collision is determined by the height of the release position, and the final velocity after collision is determined from the height of the collision point from the ground and the horizontal distance that the ball travels before it reaches the ground. With this apparatus, the performance of a high precision experiment for momentum conservation during the collision process was achieved.

1.
Physical Science Study Committee, Physics Laboratory Guide (D. C. Heath and Company, Lexington, Massachusetts, 1965);
similar apparatus is still widely used without considerable improvement at Physics laboratory classes in many high schools and colleges.
2.
PASCO, Instruction Manual and Experiment Guide for the Ballistic Pendulum/Projectile Launcher (PASCO Scientific, Roseville, California, 1993).
3.
H. Goldstein, Classical Mechanics (Addison-Wesley, New York, 1980);
see also M. L. Boas, Mathematical Methods in the Physical Sciences (Wiley, New York, 1965).
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