The trajectory of a small ball is the path followed by the ball moving under constant external force in projectile motion. In order to launch the ball at a constant velocity, a ramp is set up with wooden block to create a slope pathway for the ball to move under constant force with the support of potential energy. Plumb-line is suspended from the edge of bench and is used to aid the measurement of horizontal distance between edge of bench and position of ball impact on wooden board. To get the exact position where the ball fall, a carbon paper is placed on top of a blank paper to obtain a mark made by the ball impact.
From this experiment, it was observed that the value of x, which is the horizontal distance between the plumb-line and mark of paper increased as y, the vertical distance between the bottom of the ramp and the top of the board increased. Also, the trajectory of the ball take on the shape of a parabola. This is because there are two dimension to the ball’s motion, vertical motion and horizontal motion. Theoretically, the velocity of horizontal motion remains constant since there are no horizontal forces acting upon it. The force of gravity does not affect horizontal component of motion because gravity acts at right angle to it. On the other hand, the downward force of gravity would act upon the vertical component of motion and results in a downward acceleration related to gravitational acceleration, 9.8 ms-2.