In the Next Generation Science Standards (NGSS), Newton's laws of motion, speed, velocity, and acceleration are built up progressively from elementary school through high school under the Physical Science domain (PS2: Motion and Stability: Forces and Interactions).

1. Elementary School (Grades K–3): Qualitative Pushes and Pulls

• K-PS2-1 & K-PS2-2: Plan investigations to compare the effects of different pushes or pulls on the speed or direction of an object's motion.

• 3-PS2-1 & 3-PS2-2: Plan and conduct an investigation to provide evidence of the effects of balanced and unbalanced forces on the motion of an object, and make observations/predictions of an object's motion patterns.

• Focus: Non-mathematical introduction to how a push or pull changes whether something is moving, speeding up, slowing down, or changing direction.

2. Middle School (Grades 6–8): Newton's First, Second, and Third Laws

• MS-PS2-1 (Newton’s Third Law): Apply scientific and engineering principles to design a solution for the motion of two colliding objects. Interacting objects exert equal and opposite forces on each other.

• MS-PS2-2 (Newton’s First and Second Laws): Plan an investigation to provide evidence that the change in an object’s motion depends on the sum of the forces on the object (net force) and the mass of the object.

  • Clarification / Concepts:

    • Balanced forces (First Law): Net force is zero, so an object stays at rest or keeps moving at a constant speed in a straight line (inertia).

    • Unbalanced forces & Mass (Second Law): A larger net force causes a greater change in motion; a larger mass requires a greater force to achieve the same change in motion.

    • Requires shared reference frames and specific units. Limited to one-dimensional motion in an inertial reference frame.

3. High School (Grades 9–12): Quantitative Relationships and Conservation

• HS-PS2-1 (Newton’s Second Law): Analyze data to support the mathematical relationship among net force, mass, and acceleration (\(F_{net} = m \cdot a\)) using position or velocity time-data.

• HS-PS2-2 & HS-PS2-3 (Momentum and Collisions): Use mathematical representations for momentum conservation and apply engineering concepts to design collision-mitigation devices.

Core Vocabulary across NGSS

• Speed: The rate at which an object covers distance.

• Velocity: The speed and direction of a moving object.

• Acceleration: The rate of change of velocity.

• Net Force: The sum of all forces acting on an object.

• Inertia: The tendency to resist changes in velocity.