What class of lever is a mouse trap car?

Third class. Because they are good for speed and longer movements and are arranged: FEL; Flucrum - Effort - Load. Other examples include brooms, fishing poles, and even your knees. On the mouse trap car the fulcrum is the bar that the spring is wound upon. The effort is the pressure on the snapper's lever arm that comes from the spring unwinding, and the load is at the end of the lever arm where the string is attached, the string that gets wound around the main axle and causes the wheels to turn when the spring is released.