Standard 8.P.2: The student will demonstrate an understanding of the effects of forces on the motion and stability of an object.
8.P.2A. Conceptual Understanding: Motion occurs when there is a change in position of an object with respect to a reference point. The final position of an object is determined by measuring the change in position and direction of the segments along a trip. While the speed of the object may vary during the total time it is moving, the average speed is the result of the total distance divided by the total time taken. Forces acting on an object can be balanced or unbalanced. Varying the amount of force or mass will affect the motion of an object. Inertia is the tendency of objects to resist any change in motion.
Performance Indicators: Students who demonstrate this understanding can:
8.P.2A.1 Plan and conduct controlled scientific investigations to test how varying the amount of force or mass of an object affects the motion (speed and direction), shape, or orientation of an object.
8.P.2A.2 Develop and use models to compare and predict the resulting effect of balanced and unbalanced forces on an object’s motion in terms of magnitude and direction.
8.P.2A.3 Construct explanations for the relationship between the mass of an object and the concept of inertia (Newton’s First Law of Motion).
8.P.2A.4 Analyze and interpret data to support claims that for every force exerted on an object there is an equal force exerted in the opposite direction (Newton’s Third Law of Motion).
8.P.2A.5 Analyze and interpret data to describe and predict the effects of forces (including gravitational and friction) on the speed and direction of an object.
8.P.2A.6 Use mathematical and computational thinking to generate graphs that represent the motion of an object’s position and speed as a function of time.
8.P.2A.7 Use mathematical and computational thinking to describe the relationship between the speed and velocity (including positive and negative expression of direction) of an object in determining average speed (v=d/t).