Answer: (d)
Explanation:
Given
Mass of object 
Speed of object 
Mass of object at rest 
Suppose after collision, speed is v
conserving momentum

Initial kinetic energy

Final kinetic energy

So, it is clear there is decrease in kinetic energy . Thus, energy decreases and velocity becomes 2 m/s.
Answer:
These energy exchanges are not changes in kinetic energy. They are changes in bonding energy between the molecules. If heat is coming into a substance during a phase change, then this energy is used to break the bonds between the molecules of the substance.
Answer:The most important process would be the ice crystal process
Explanation:
Ice crystal process also called Bergeron process requires numerous small water drops that are supercooled, which is a common feature in clouds between about 0° and -20°C or below, along with a small number of ice crystals. Therefore because the collision-coalescence process requires that cloud droplets be of varying size so that drops will fill at different speeds, the most important process would be the ice crystal process.
The splitting of the atomic nucleus into parts