Skip to content
Marlbridge

AP® Physics 1: Algebra-Based · Unit 2 · Topic 2.5

Newton’s Second Law: Topic Checklist (Physics 1 2.5)

Specific “I can…” statements for Newton’s second law in the algebra-based course, each linked to the guide section and practice question that tests it.

Work through the list without notes. If you cannot do a statement, follow its link, then come back. Guide = study guide; Practice = practice questions.

Understanding

  • I can explain what “unbalanced forces” means and why they always change a system’s velocity. (Guide: “From balanced to unbalanced forces”)
  • I can state Newton’s second law in words, including that the acceleration points along the net force, not necessarily along the velocity. (Guide: “Newton’s second law”; Practice Q3)
  • I can explain why internal forces cannot change the velocity of a system’s centre of mass, using the two skaters as an example. (Guide: “Choosing the system”)
  • I can explain why ma never appears as an arrow on a free-body diagram. (Guide: Figure 2; “Common misconceptions”)

Skills

  • I can draw a free-body diagram with separate, labelled arrows and use it to write ΣF = ma along each axis. (Guide: Worked example 1; Practice Q4)
  • I can find the net force from several forces with signs before dividing by the mass. (Practice Q1, Q4)
  • I can choose a whole system to find an acceleration, then a single object to find a tension or contact force. (Guide: Worked example 2; Practice Q5)
  • I can predict the factor by which the acceleration changes when the net force and the mass both change. (Guide: “Functional dependence”; Practice Q2)
  • I can find a mass from the slope of an acceleration–force graph. (Guide: Figure 1; Practice Q6)
  • I can derive symbolic expressions for the acceleration and tension of a connected system and test them with limiting cases. (Guide: Worked example 3; Practice Q7)

Reasoning

  • I can use a force–acceleration graph to support or refute a claim about friction. (Practice Q6)
  • I can justify why a contact force between two pushed blocks depends on which block is pushed. (Practice Q5)
  • I can explain why the forces on an object can be balanced along one axis but unbalanced along another, and what that does to its motion. (Practice Q7)

All ticked? Move on to Topic 2.6, Gravitational Force, or return to the course roadmap.

AP® and Advanced Placement® are trademarks registered by the College Board, which is not affiliated with, and does not endorse, this website. Marlbridge is an independent tuition provider. It is not an authorized AP course provider, an AP school or an exam centre, and these resources are not official College Board materials. Reading them or doing simulations does not meet the laboratory requirement of an AP science course.