If you find you need to take into account the effects of air friction, it fits into our constant acceleration model as a small acceleration which opposes the velocity. In other words, it has direction opposite the instantaneous velocity, and since the direction of the instantaneous velocity changes, so does the direction of the acceleration due to air friction. Models of air friction generally include a dependence on the magnitude as well as the direction of the velocity. It is beyond the scope of this course to take air friction into account properly. If you take it into account here, it will be in an approximate way.
Meter sticks are in the back of the lab.
When using the launcher, use the medium range setting. Launch the projectile at with respect to the horizontal. It should hit the table before bouncing off somewhere. If it doesn't, mount the launcher further from the end of the table. Now you know approximately where the ball hits the table for a horizontal launch.