Answer: They SUPERIMPOSE themselves.
Step-by-step explanation:
When two or more waves are at the same place at the same time, They SUPERIMPOSE themselves. This follows a principle known as superposition, which states that when two more waves are traveling through the same medium at the same time,they pass through each other without being disturbed( that is, they superimpose). Therefore, in order to calculate the net displacement of the medium, the sum of the individual wave displacements is determined.