AP Physics 1 Flashcards: Elastic And Inelastic Collisions

What this deck covers

This deck focuses on Elastic And Inelastic Collisions, giving you a quick way to review the definitions, rules, and examples that matter most for AP Physics 1.

How to use these flashcards

Work through these flashcards in short sessions. Try to answer each prompt before flipping the card, then revisit any cards you miss until the explanation feels automatic.

Flashcard 1: What do we call a collision where objects move together after impact?

Answer: Perfectly inelastic collision. Maximum energy loss occurs when objects stick and move together.

Flashcard 2: State the formula for conservation of momentum in a collision.

Answer: $m_1v_1 + m_2v_2 = m_1v_1' + m_2v_2'$. Total momentum before equals total momentum after collision.

Flashcard 3: What is the key principle that distinguishes collision types?

Answer: Conservation of kinetic energy. Kinetic energy conservation determines elastic versus inelastic classification.

Flashcard 4: What quantity is always conserved in both elastic and inelastic collisions?

Answer: Momentum. Newton's third law ensures momentum conservation in isolated systems.

Flashcard 5: What do we call the loss of kinetic energy in an inelastic collision?

Answer: Energy dissipation. Kinetic energy converts to heat, sound, or deformation.

Flashcard 6: Name a real-world example of an inelastic collision.

Answer: A car crash. Deformation and energy loss characterize real-world inelastic impacts.

Flashcard 7: What do we call a collision where objects move together after impact?

Answer: Perfectly inelastic collision. Maximum energy loss occurs when objects stick and move together.

Flashcard 8: In an elastic collision, what happens to the relative speed of approach and separation?

Answer: They are equal. Defines elastic collision: approach speed equals separation speed.

Flashcard 9: What is the formula for the coefficient of restitution?

Answer: $e = \frac{v_2' - v_1'}{v_1 - v_2}$. Relates relative velocities before and after collision impact.

Flashcard 10: In a collision, if kinetic energy is lost, what type of collision is it?

Answer: Inelastic. Energy converts to heat, sound, or deformation during collision.

Flashcard 11: In an elastic collision, what happens to the relative speed of approach and separation?

Answer: They are equal. Defines elastic collision: approach speed equals separation speed.

Flashcard 12: What is the value of the coefficient of restitution for a perfectly inelastic collision?

Answer:

1. No separation occurs; objects move together with zero relative velocity.

Flashcard 13: Identify the primary characteristic of a perfectly elastic collision.

Answer: Total kinetic energy is conserved. No kinetic energy is lost to other forms like heat or sound.

Flashcard 14: What happens to total system momentum in any type of collision?

Answer: It remains constant. Newton's third law ensures momentum conservation in all collisions.

Flashcard 15: For an inelastic collision, is the coefficient of restitution less than, equal to, or greater than 1?

Answer: Less than 1. Energy loss reduces the relative separation speed after collision.

Flashcard 16: In a collision where two cars stick together, what type of collision is it?

Answer: Perfectly inelastic collision. Objects join together, maximizing kinetic energy loss in collision.

Flashcard 17: During a collision, if the total kinetic energy increases, what might be occurring?

Answer: External work performed on the system. Additional energy input from explosion or spring release mechanism.

Flashcard 18: What is the formula for the coefficient of restitution?

Answer: $e = \frac{v_2' - v_1'}{v_1 - v_2}$. Relates relative velocities before and after collision impact.

Flashcard 19: What is the definition of an elastic collision?

Answer: A collision where total kinetic energy is conserved. Both momentum and kinetic energy are preserved throughout the collision.

Flashcard 20: In a perfectly inelastic collision, what happens to the colliding objects?

Answer: They stick together post-collision. Objects combine into a single mass moving with common velocity.

Flashcard 21: In a collision, if the objects do not stick and kinetic energy is conserved, what type is it?

Answer: Elastic collision. Objects separate after collision with kinetic energy preserved.

Flashcard 22: In which type of collision might sound, heat, or deformation occur?

Answer: Inelastic collision. Energy converts to heat, sound, and permanent deformation.

Flashcard 23: What quantity is always conserved in both elastic and inelastic collisions?

Answer: Momentum. Newton's third law ensures momentum conservation in isolated systems.

Flashcard 24: In a collision, if the objects do not stick and kinetic energy is conserved, what type is it?

Answer: Elastic collision. Objects separate after collision with kinetic energy preserved.

Flashcard 25: What is the key difference between elastic and inelastic collisions regarding energy?

Answer: Elastic conserves kinetic energy; inelastic does not. Elasticity is defined by whether kinetic energy is preserved.

Flashcard 26: What is the definition of an elastic collision?

Answer: A collision where total kinetic energy is conserved. Both momentum and kinetic energy are preserved throughout the collision.

Flashcard 27: In which type of collision might sound, heat, or deformation occur?

Answer: Inelastic collision. Energy converts to heat, sound, and permanent deformation.

Flashcard 28: In a perfectly elastic collision, how does the kinetic energy before compare to after?

Answer: It is the same. Perfect elasticity means no energy is lost during collision.

Flashcard 29: In a perfectly inelastic collision, what happens to the colliding objects?

Answer: They stick together post-collision. Objects combine into a single mass moving with common velocity.

Flashcard 30: In a collision, if kinetic energy is lost, what type of collision is it?

Answer: Inelastic. Energy converts to heat, sound, or deformation during collision.

Flashcard 31: Identify the primary characteristic of a perfectly elastic collision.

Answer: Total kinetic energy is conserved. No kinetic energy is lost to other forms like heat or sound.

Flashcard 32: In a collision where two cars stick together, what type of collision is it?

Answer: Perfectly inelastic collision. Objects join together, maximizing kinetic energy loss in collision.

Flashcard 33: Name a real-world example of an inelastic collision.

Answer: A car crash. Deformation and energy loss characterize real-world inelastic impacts.

Flashcard 34: State the equation for kinetic energy conservation in elastic collisions.

Answer: $\frac{1}{2}m_1v_1^2 + \frac{1}{2}m_2v_2^2 = \frac{1}{2}m_1v_1'^2 + \frac{1}{2}m_2v_2'^2$. Total kinetic energy before collision equals total after collision.

Flashcard 35: Name a real-world example of an elastic collision.

Answer: Colliding billiard balls. Hard spheres approximate elastic behavior in ideal conditions.

Flashcard 36: What is the result when two objects collide elastically and their masses are equal?

Answer: They swap velocities. Equal masses in elastic collision exchange velocities completely.

Flashcard 37: What is the key difference between elastic and inelastic collisions regarding energy?

Answer: Elastic conserves kinetic energy; inelastic does not. Elasticity is defined by whether kinetic energy is preserved.

Flashcard 38: During a collision, if the total kinetic energy increases, what might be occurring?

Answer: External work performed on the system. Additional energy input from explosion or spring release mechanism.

Flashcard 39: What is the definition of an inelastic collision?

Answer: A collision where total kinetic energy is not conserved. Momentum is conserved, but some kinetic energy converts to other forms.

Flashcard 40: What happens to total system momentum in any type of collision?

Answer: It remains constant. Newton's third law ensures momentum conservation in all collisions.

Flashcard 41: What do we call the loss of kinetic energy in an inelastic collision?

Answer: Energy dissipation. Kinetic energy converts to heat, sound, or deformation.

Flashcard 42: For an inelastic collision, is the coefficient of restitution less than, equal to, or greater than 1?

Answer: Less than 1. Energy loss reduces the relative separation speed after collision.

Flashcard 43: What is the value of the coefficient of restitution for a perfectly inelastic collision?

Answer:

1. No separation occurs; objects move together with zero relative velocity.

Flashcard 44: State the formula for conservation of momentum in a collision.

Answer: $m_1v_1 + m_2v_2 = m_1v_1' + m_2v_2'$. Total momentum before equals total momentum after collision.

Flashcard 45: What happens to the kinetic energy in a perfectly inelastic collision?

Answer: It is not conserved. Maximum energy loss occurs when objects stick together.

Flashcard 46: State the equation for kinetic energy conservation in elastic collisions.

Answer: $\frac{1}{2}m_1v_1^2 + \frac{1}{2}m_2v_2^2 = \frac{1}{2}m_1v_1'^2 + \frac{1}{2}m_2v_2'^2$. Total kinetic energy before collision equals total after collision.

Flashcard 47: What is the key principle that distinguishes collision types?

Answer: Conservation of kinetic energy. Kinetic energy conservation determines elastic versus inelastic classification.

Flashcard 48: What happens to the kinetic energy in a perfectly inelastic collision?

Answer: It is not conserved. Maximum energy loss occurs when objects stick together.

Flashcard 49: What is the result when two objects collide elastically and their masses are equal?

Answer: They swap velocities. Equal masses in elastic collision exchange velocities completely.

Flashcard 50: Name a real-world example of an elastic collision.

Answer: Colliding billiard balls. Hard spheres approximate elastic behavior in ideal conditions.

Flashcard 51: What is the definition of an inelastic collision?

Answer: A collision where total kinetic energy is not conserved. Momentum is conserved, but some kinetic energy converts to other forms.

Flashcard 52: In a perfectly elastic collision, how does the kinetic energy before compare to after?

Answer: It is the same. Perfect elasticity means no energy is lost during collision.