Total Kinetic Energy ($TKE$) of an object in motion is conserved
Inelastic
Total Kinetic Energy ($TKE$) of an object in motion is not conserved
Some of it is transformed into other types of energy e.g heat, sound and light
Example Questions
A bear of $24.2kg$ is travelling east at $6.66m\space s^{-1}$ when it collides with something sticky and disgusting which has mass $8.47kg$ and is travelling west at $7.77m\space s^{-1}$. They coalesce to form a sticky, disgusting bear mass thing (sdbmt).
What is the final velocity of the sdbmt?
$6.95m s^{-1}$
Show by calculation whether the collision was elastic or inelastic. Justify your answer.