Abstract: In view of the inquiry experiment of horizontal projectile motion in High School Physics Teaching Edition Compulsory 2, the paper points out the disadvantages in the experience device for the teaching material demonstration, and improves the demonstration apparatus of the horizontal projectile motion. After the improvement, the movements of the horizontal projectile motion at the horizontal direction and vertical direction can be observed visually. The new instrument breaks through the main points and difficulties in the teaching of horizontal projectile motion. The instrument is operated simply, and the demonstration effect is obvious.

Key words: horizontal projectile motion, uniform linear motion, motion of free falling body, decomposition, demonstration instrument, improvement