Students investigate Newton's Second Law of Motion using a computer model from the University of Colorado PHET. This simulation allows students to change the mass of objects that collide. This activity can be used as an activator to build knowledge for concepts in physics, physical science, momentum, forces, and F=MA. Students write an open response, using a claim - evidence - reasoning (CER) template. This is an editable .rtf file. You can upload it to Google Docs and share it through Google Cl