When you trip, your foot stops, but your body continues to move forward due to the principle of inertia. Inertia is the tendency of an object to resist changes in its motion. In this case, your body is in motion prior to tripping, and when your foot stops abruptly upon hitting an obstacle, your body wants to continue moving forward due to its inertia. This causes your body to "carry" forward for some distance before eventually coming to a stop or experiencing the effects of another force (e.g., gravity or friction).
