Grade 8Science

Focus: In this unit, students investigate the phenomenon of collisions and what happens to the objects that collide. The subtitle of this unit is Why do things get damaged when they hit each other? This is a phenomenon that students experience when they see any two objects collide. What happens to the shape each of the colliding objects? How does the mass of each object affect the damage in a collision? How do the speeds of the two objects affect the nature of the collision? Can we use the concept of force to help explain collisions? This unit allows students to observe collision phenomena in detail and then start asking questions, formulating explanations, setting up and conducting activities and research, and working with classmates to analyze the shared experience and formulate new questions and developing new strategies for answering them. Students explore concepts that include the following:


  • What causes changes in the motion and shape of colliding objects?
  • Do all objects change shape or bend when they are pushed in a collision?
  • How much does doubling the speed or doubling the mass affect the kinetic energy of an object and the resulting damage it can do in a collision?

As students move through their day-to-day activities, they will also read Core Knowledge literacy selections. These include factual articles, history of the sciences, art and literature, spotting bad science in the media and advertisements, graphics comprehension, research-type articles, reliability of sources, and other areas of science literacy.

Lesson Numbers:

  • Teacher Guide: 16 Lessons
  • Student Reader: 5 Collections

Lesson time:

  • Lessons can be completed in one or more class periods.
  • A Pacing Guide, found in Online Resources, offers the suggestion that the entire unit should take about 33 days if class is held each day.
  • A complete list of materials needed to complete the unit is also provided in the Online Resources.
  • The Core Knowledge Student Reader includes on reading collection per week for every week of the unit. A week’s reading collection related to the lessons completed in the previous week.
    • The reading is assigned at the beginning of the week with the accompanying writing exercise due at the end of the week.
    • The reading and writing exercises are designed to be completed by students independently with brief, supporting, teacher-facilitated discussions at the beginning, midpoint, and end of the week.

Additional Search Terms for the Student Reader:

• scientific literacy • speed • mass • collision • kinetic energy • force • velocity • newton • breaking point • elastic limit • deform • potential energy • projectile • flammability • air resistance • engineering design • constraint • criteria • shareholders • nonfiction • informational text


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