Specially designed for teaching basic physics in middle schools and universities, the "flat throwing motion" is derived from the blackboard and applied to real-life scenarios: students build in 3 minutes, collect in 1 minute, and obtain trajectories in 10 seconds with an error of ≤ 2%. The laser triggers an instant flash of red light, and students can intuitively see the "horizontal uniform speed". Experimental case: Verify the uniform speed of horizontal motion and the free fall of vertical motion. Measure the acceleration due to gravity g (fitted by y=189gt ²). Explore the quantitative relationship between initial velocity v ₀ and horizontal range x. Extension: Demonstration of oblique throwing motion (simply replace the inclined track).