Some of the snowball's initial kinetic energy is lost in form of frictional, heating or due to deformation of bodies, once inelastic collision has happened.
Hence, the kinetic energy of the snowball and sign after collision is less than the kinetic energy of the snowball before collision.
This collision, where the two bodies that collide and they stick together after collision is called inelastic collision.
The one where the two bodies don't stick together after collision is called elastic collision.
In elastic collision, both momentum and kinetic energy are conserved with the sum of each of these quantities before collision being equal to the sum after collision.
But, when it comes to inelastic collision, only momentum is conserved.
The kinetic energy isn't conserved as part of the initial kinetic energy is lost in some form to ensure that the the kinetic energy of the snowball plus sign system after collision is smaller compared to the kinetic energy of the snowball before collision.
The forms in which the kinetic energy is lost include through heating effects arising from a vibration of the atoms of the two bodies involved, through the deformation of either or both bodies etc.
<span>A hypothesis that can be tested through experimentation. The results of experimentation lead to changes in scientific knowledge.
The goal of science is to understand the natural world. To achieve this goal, scientists make certain assumptions. They assume that Nature can be understood by systematic study., And Scientific ideas are open to review as well. Strong scientific ideas stand the test of time and that Science can not give answers to all questions.
Scientists think of nature as a unique system controlled by natural laws. And by discovering natural laws, scientists strive to increase their understanding of the entire natural world and the laws of nature are expressed as scientific laws by counting themselves as a scientific law is a statement that describes as happening under certain conditions in nature.</span>