Clarification Statement - S.MS.PS.2.1.CS:
Examples of practical problems could include the impact of collisions between two cars, between a car and stationary objects, and between a meteor and a space vehicle.

Assessment Boundary - S.MS.PS.2.1.AB:
Assessment is limited to vertical or horizontal interactions in one dimension.

Science and Engineering Practices - 6-8.SEP6.2:
Apply scientific ideas or principles to design an object, tool, process or system.

Disciplinary Core Ideas - S.MS.PS.2.1.DCI:
PS2.A: Forces and Motion •For any pair of interacting objects, the force exerted by the first object on the second object is equal in strength to the force that the second object exerts on the first, but in the opposite direction (Newton’s third law).

Crosscutting Concepts - CC3.3:
Models can be used to represent systems and their interactions—such as inputs, processes and outputs—and energy and matter flows within systems.

Clarification Statement - S.MS.PS.2.2.CS:
Emphasis is on balanced (Newton’s First Law) and unbalanced forces in a system, qualitative comparisons of forces, mass and changes in motion (Newton’s Second Law), frame of reference, and specification of units.

Assessment Boundary - S.MS.PS.2.2.AB:
Assessment is limited to forces and changes in motion in one-dimension in an inertial reference frame and to change in one variable at a time. Assessment does not include the use of trigonometry.

Science and Engineering Practices - 6-8.SEP3.1:
Plan an investigation individually and collaboratively, and in the design: identify independent and dependent variables and controls, what tools are needed to do the gathering, how measurements will be recorded, and how many data are needed to support a c

Disciplinary Core Ideas - S.MS.PS.2.2.DCI:
PS2.A: Forces and Motion •The motion of an object is determined by the sum of the forces acting on it; if the total force on the object is not zero, its motion will change. The greater the mass of the object, the greater the force needed to achieve the same change in motion. For any given object, a larger force causes a larger change in motion. •All positions of objects and the directions of forces and motions must be described in an arbitrarily chosen reference frame and arbitrarily chosen units of size. In order to share information with other people, these choices must also be shared.

Crosscutting Concepts - CC6.2:
Explanations of stability and change in natural or designed systems can be constructed by examining the changes over time and forces at different scales.

Clarification Statement - S.MS.PS.2.3.CS:
Examples of devices that use electric and magnetic forces could include electromagnets, electric motors, or generators. Examples of data could include the effect of the number of turns of wire on the strength of an electromagnet, or the effect of increasi

Assessment Boundary - S.MS.PS.2.3.AB:
Assessment about questions that require quantitative answers is limited to proportional reasoning and algebraic thinking.

Science and Engineering Practices - 6-8.SEP1.1:
Ask questions that can be investigated within the scope of the classroom, outdoor environment, and museums and other public facilities with available resources and, when appropriate, frame a hypothesis based on observations and scientific principles.

Disciplinary Core Ideas - S.MS.PS.2.3.DCI:
PS2.B: Types of Interactions •Electric and magnetic (electromagnetic) forces can be attractive or repulsive, and their sizes depend on the magnitudes of the charges, currents, or magnetic strengths involved and on the distances between the interacting objects.

Crosscutting Concepts - CC2.5:
Cause and effect relationships may be used to predict phenomena in natural or designed systems.

Clarification Statement - S.MS.PS.2.4.CS:
Examples of evidence for arguments could include data generated from simulations or digital tools; and charts displaying mass, strength of interaction, distance from the Sun, and orbital periods of objects within the solar system.

Assessment Boundary - S.MS.PS.2.4.AB:
Assessment does not include Newton’s Law of Gravitation or Kepler’s Laws.

Science and Engineering Practices - 6-8.SEP7.1:
Construct and present oral and written arguments supported by empirical evidence and scientific reasoning to support or refute an explanation or a model for a phenomenon or a solution to a problem.

Disciplinary Core Ideas - S.MS.PS.2.4.DCI:
PS2.B: Types of Interactions •Gravitational forces are always attractive. There is a gravitational force between any two masses, but it is very small except when one or both of the objects have large mass—e.g., Earth and the sun.

Crosscutting Concepts - CC3.3:
Models can be used to represent systems and their interactions—such as inputs, processes and outputs—and energy and matter flows within systems.

Clarification Statement - S.MS.PS.2.5.CS:
Examples of this phenomenon could include the interactions of magnets, electrically-charged strips of tape, and electrically-charged pith balls. Examples of investigations could include first-hand experiences or simulations. Emphasis should be on using a

Assessment Boundary - S.MS.PS.2.5.AB:
Assessment is limited to electric and magnetic fields, and limited to qualitative evidence for the existence of fields.

Science and Engineering Practices - 6-8.SEP3.3:
Conduct an investigation and evaluate the experimental design to produce data to serve as the basis for evidence that can meet the goals of the investigation.

Disciplinary Core Ideas - S.MS.PS.2.5.DCI:
PS2.B: Types of Interactions •Forces that act at a distance (electric, magnetic, and gravitational) can be explained by fields that extend through space and can be mapped by their effect on a test object (a charged object, or a ball, respectively).

Crosscutting Concepts - CC2.5:
Cause and effect relationships may be used to predict phenomena in natural or designed systems.