Interference is a condition that occurs when

a) one side of a wave moves at a different speed than the other b) a wave encounters an obstruction c) two or more waves overlap and combine d) the source of the wave’s vibration loses energy

The correct answer is (c).

Explanation:

Interference is a phenomenon in which there is overlapping of the waves occur.

The amplitude of the result wave can be maximum and minimum.

Interference are of two types: Destructive and constructive.

When the resulting wave having maximum amplitude then interference is said to be constructive.

When the resulting wave having minimum amplitude then interference is said to be Destructive.

Therefore, the correct answer is c.

the bal will not change its velocity.

when heated, the valance electrons increased their speed and transferred the heat from electron to electron.   i just took the test.