the table so that it can fire off the table edge. Load the spring gun and fire one shot to find the approximate range of the projectile . Tape a piece of paper down at the impact point . Fire the ball five times. Observe and mark the indentations in the paper where the ball hits. Be careful to make sure that the apparatus does not move between trials . Measure the horizontal distance that the ball travels and the vertical distance that it falls . Note that you need to measure from the end of the spring gun, not the end of the table. You can measure to the edge of the table, and then use a plumb bob to determine the point directly under the edge of the table so that you can measure from there . Use this information to compute the velocity of the ball