Learning Goal
Elastic and Inelastic Collisions
Teacher tools for this standard
Lesson Plan · Guided Notes · Exit Ticket · Re-teach · Homework
Teacher tools for this standard
Lesson Plan · Guided Notes · Exit Ticket · Re-teach · Homework
- Lesson Plan →Objectives, pacing and practice, built from this lesson's brief.
- Guided Notes →One page your students fill in and keep.
- Exit Ticket →Three items at the end of class. No student accounts.
- Re-teach →After an exit ticket: who missed what, and what to do tomorrow.
- Homework →Assign practice; it grades itself.
"In an **elastic collision**, the objects separate after impact and don't lose any of their kinetic energy."
"An **inelastic collision** is one in which kinetic energy is not conserved. A perfectly inelastic collision (also sometimes called completely or maximally inelastic) is one in which objects stick together after impact, and the maximum amount of kinetic energy is lost."
"$m_1 \vec{v}_1 + m_2 \vec{v}_2 = m_1 \vec{v}\,'_1 + m_2 \vec{v}\,'_2$" — conservation of momentum for two objects in a one-dimensional collision; for a perfectly inelastic collision this becomes "$m_1 \vec{v}_1 + m_2 \vec{v}_2 = (m_1 + m_2)\vec{v}\,'$".
"To avoid rotation, we consider only the scattering of **point masses**—that is, structureless particles that cannot rotate or spin."
"Because momentum is conserved, the components of momentum along the *x*- and *y*-axes ... will also be conserved."
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"In an elastic collision, the objects separate after impact and don't lose any of their kinetic energy."
"An inelastic collision is one in which kinetic energy is not conserved. A perfectly inelastic collision (also sometimes called completely or maximally inelastic) is one in which objects stick together after impact, and the maximum amount of kinetic energy is lost."
"$m_1 \vec{v}_1 + m_2 \vec{v}_2 = m_1 \vec{v},'_1 + m_2 \vec{v},'_2$" — conservation of momentum for two objects in a one-dimensional collision; for a perfectly inelastic collision this becomes "$m_1 \vec{v}_1 + m_2 \vec{v}_2 = (m_1 + m_2)\vec{v},'$".
"To avoid rotation, we consider only the scattering of point masses—that is, structureless particles that cannot rotate or spin."
"Because momentum is conserved, the components of momentum along the x- and y-axes ... will also be conserved."
What you'll learn
- Distinguish between elastic and inelastic collisions, and identify a perfectly inelastic collision
- State that momentum is conserved in all collisions while kinetic energy is conserved only in elastic collisions
- Apply m₁v₁ + m₂v₂ = m₁v'₁ + m₂v'₂ to solve one-dimensional collision problems, with correct velocity signs
- Apply the perfectly inelastic simplification m₁v₁ + m₂v₂ = (m₁+m₂)v' when objects stick together
- Set up a two-dimensional collision of point masses by conserving momentum separately along the x- and y-axes
Slides
Step through the lesson, or watch it as a narrated video
Slides
In development
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