"In physics, a collision is any event in which two or more bodies exert forces on each other in a relatively short time."
The interactions between two or more objects that result in a change in their momentum.
Kinematics: The study of motion and its causes, without considering the forces involved.
Dynamics: The study of the causes of motion and the effects of those causes, including forces, energy, and momentum.
Force: A push or pull on an object, which has both magnitude and direction.
Newton's Laws of Motion: A set of principles formulated by Sir Isaac Newton, describing the relationship between an object's motion and the forces acting upon it.
Conservation of Momentum: The principle that the total momentum of a closed system of objects (or particles) remains constant, as long as no external forces act upon it.
Inelastic Collision: A collision in which two objects stick together after colliding, resulting in a final velocity that is less than the initial velocity.
Elastic Collision: A collision in which two objects bounce off each other, with no loss of energy, resulting in a final velocity that is equal to the initial velocity.
Center of Mass: The point in a system with multiple objects where the mass appears to be concentrated.
Coefficient of Restitution: A measurement of the elasticity of a collision between two objects, expressed as the ratio of the final to initial relative velocity of the objects.
Impulse: The change in momentum of an object, caused by a force acting on it over a period of time.
Angular Momentum: A measure of the rotations of an object about its center of mass.
Torque: The force that causes an object to rotate or twist around an axis, often measured in Newton-meters.
Rotational Kinetic Energy: The energy associated with an object's motion in a circle or around an axis of rotation.
Gravitational Potential Energy: The energy stored in an object due to its position in a gravitational field.
Work: The amount of energy transferred to an object by a force acting on it, measured in Joules or other units.
Power: The rate at which work is done, often measured in Watts.
Friction: A force that opposes motion between two surfaces in contact.
Air Resistance: A type of friction that opposes the motion of an object through the air, often becoming significant for high-speed objects.
Simple Harmonic Motion: A type of motion in which an object oscillates back and forth around a central point, due to a restoring force.
Newton's Law of Universal Gravitation: A fundamental principle of physics stating that every particle in the universe attracts every other particle with a force directly proportional to the product of their masses and inversely proportional to the square of the distance between them.
Elastic Collision: A collision in which the total kinetic energy and momentum of the system are conserved.
Inelastic Collision: A collision in which the kinetic energy is not conserved, but momentum is conserved.
Perfectly Inelastic Collision: A type of inelastic collision in which two objects stick together and move as a single object after the collision.
Partially Inelastic Collision: A type of inelastic collision in which some kinetic energy is lost and the objects do not stick together after the collision.
Oblique Collision: A type of collision in which the two objects collide at an angle instead of head on.
Head-On Collision: A type of collision in which the two objects collide straight on, with no angle involved.
Rear-End Collision: A type of collision where one object hits the other from behind.
Glancing Collision: A type of collision in which the two objects only strike each other partly, and then change their direction of motion.
Direct Collision: A type of collision in which the two objects collide directly without any intervention.
Indirect Collision: A type of collision in which the two objects collide indirectly through some intermediary.
Compound Collision: A type of collision in which multiple collisions occur, leading to complex outcomes.
Coulomb Collisions: A type of collision between charged particles, which exchange energy and momentum through electromagnetic interactions.
Gravitational Collisions: A type of collision in which objects are attracted to each other through gravity and collide when they come close enough.
Hard Sphere Collision: A type of collision in which perfect spheres collide with each other.
Soft Sphere Collision: A type of collision in which deformable spheres collide with each other.
Non-Conservative Collisions: A type of collision in which some work is done by external forces leading to a loss of total energy.
Conservative Collisions: A type of collision in which there is no work done by external forces and as a result, the total energy is conserved.
"Although the most common use of the word collision refers to incidents in which two or more objects collide with great force..."
"The scientific use of the term implies nothing about the magnitude of the force."
"In physics, collisions can be classified by the change in the total kinetic energy of the system before and after the collision."
"If most or all of the total kinetic energy is lost (dissipated as heat, sound, etc. or absorbed by the objects themselves), the collision is said to be inelastic."
"Such collisions involve objects coming to a full stop. An example of such a collision is a car crash..."
"This is by design, for the safety of the occupants and bystanders should a crash occur - the frame of the car absorbs the energy of the crash instead."
"An example of such a collision is a car crash, as cars crumple inward when crashing, rather than bouncing off of each other."
"If most of the kinetic energy is conserved (i.e. the objects continue moving afterwards), the collision is said to be elastic."
"An example of this is a baseball bat hitting a baseball - the kinetic energy of the bat is transferred to the ball, greatly increasing the ball's velocity."
"The sound of the bat hitting the ball represents the loss of energy."
"And if all of the total kinetic energy is conserved (i.e. no energy is released as sound, heat, etc.), the collision is said to be perfectly elastic."
"Such a system is an idealization and cannot occur in reality, due to the second law of thermodynamics."
"For the safety of the occupants and bystanders, the frame of the car absorbs the energy of the crash instead."
"If most or all of the total kinetic energy is lost... the collision is said to be inelastic."
"If most of the kinetic energy is conserved... the collision is said to be elastic."
"An example of this is a baseball bat hitting a baseball - the kinetic energy of the bat is transferred to the ball..."
"The sound of the bat hitting the ball represents the loss of energy."
"Such a system is an idealization and cannot occur in reality..."
"The difference lies in the change of total kinetic energy – whether it is lost or conserved."