All Flashcards
What are the key differences between elastic and inelastic collisions?
Elastic: KE is conserved | Inelastic: KE is not conserved, converted to other forms of energy.
Compare and contrast momentum and kinetic energy.
Momentum: vector, p = mv, always conserved in collisions (no external force) | Kinetic Energy: scalar, KE = 1/2mv^2, conserved only in elastic collisions
Differentiate between the equations used for conservation of momentum in elastic and inelastic collisions (objects stick together).
Elastic: | Inelastic (stick together):
What is the difference between solving for final velocities in 1D vs 2D elastic collisions?
1D: Solve one equation for one unknown. | 2D: Resolve velocities into x and y components and solve two equations for two unknowns.
Compare the role of external forces in conservation of momentum and conservation of energy.
Conservation of Momentum: Momentum is conserved if there is no external force. | Conservation of Energy: Energy is conserved if there is no external force doing work on the system.
What happens if the net external force on a system is zero during a collision?
The total momentum of the system is conserved.
What is the effect of kinetic energy not being conserved in a collision?
The collision is inelastic, and some kinetic energy is converted into other forms of energy like heat, sound, or deformation.
What happens when two objects stick together after a collision?
The collision is inelastic, and they move with a common final velocity.
What is the effect of increasing the mass of an object on its momentum if velocity remains constant?
The momentum of the object increases proportionally (p = mv).
What is the effect of increasing the velocity of an object on its kinetic energy if mass remains constant?
The kinetic energy of the object increases by the square of the velocity (KE = 1/2mv^2).
Define momentum.
Momentum is the product of an object's mass and velocity: p = mv. It is a vector quantity.
What is an elastic collision?
A collision where both momentum and kinetic energy are conserved.
What is an inelastic collision?
A collision where momentum is conserved, but kinetic energy is not. Some KE is converted to other forms of energy.
Define 'conservation of momentum'.
If the net external force on a system is zero, the total momentum of the system remains constant: pinitial = pfinal
What is kinetic energy (KE)?
The energy an object possesses due to its motion. KE = 1/2 * mv^2