# When two pulses meet up with each other

### Wave interference review (article) | Khan Academy

When two pulses meet up with each other while moving through the same medium, they have a tendency to bounce off each other and return back to their origin. When two pulses meet up with each other while moving through the same Constructive interference occurs when a crest meets up with another crest at a. When a wave has lost some of its energy to heating up the medium through . ( True/False) When two pulses meet up with each other while moving through the.

### Transverse Pulses - Grade 10 [CAPS]

Draw a position vs. Draw a velocity vs. Transmission and Reflection of a Pulse at a Boundary What happens when a pulse travelling in one medium finds that medium is joined to another?

Two ropes Find two different ropes and tie both ropes together. Hold the joined ropes horizontally and create a pulse by flicking the rope up and down.

What happens to the pulse when it encounters the join? When a pulse is transmitted from one medium to another, like from a thin rope to a thicker one, the nature of the pulse will change where it meets the boundary of the two media i. Part of the pulse will be reflected and part of it will be transmitted. The incident pulse is the one that arrives at the boundary. The reflected pulse is the one that moves back, away from the boundary.

The transmitted pulse is the one that moves into the new medium, away from the boundary. The speed of the pulse depends on the mass of the rope; the pulse is faster in the thinner rope and slower in the thick rope. When the speed of the pulse increases, the pulse length will increase.

Show Me Some Science! Constructive and Destructive Interference

If the speed decreases, the pulse length will decrease. Reflection and transmission of a pulse at the boundary between two media. Consider a pulse moving from a thin rope to a thick rope. When the waves move away from the point where they came together, in other words, their form and motion is the same as it was before they came together.

Constructive interference Constructive interference occurs whenever waves come together so that they are in phase with each other.

## Wave interference review

This means that their oscillations at a given point are in the same direction, the resulting amplitude at that point being much larger than the amplitude of an individual wave. For two waves of equal amplitude interfering constructively, the resulting amplitude is twice as large as the amplitude of an individual wave.

For waves of the same amplitude interfering constructively, the resulting amplitude is times larger than the amplitude of an individual wave. Constructive interference, then, can produce a significant increase in amplitude. The following diagram shows two pulses coming together, interfering constructively, and then continuing to travel as if they'd never encountered each other. Another way to think of constructive interference is in terms of peaks and troughs; when waves are interfering constructively, all the peaks line up with the peaks and the troughs line up with the troughs.

Destructive interference Destructive interference occurs when waves come together in such a way that they completely cancel each other out. When two waves interfere destructively, they must have the same amplitude in opposite directions. When there are more than two waves interfering the situation is a little more complicated; the net result, though, is that they all combine in some way to produce zero amplitude.

In general, whenever a number of waves come together the interference will not be completely constructive or completely destructive, but somewhere in between. It usually requires just the right conditions to get interference that is completely constructive or completely destructive.

The following diagram shows two pulses interfering destructively. Again, they move away from the point where they combine as if they never met each other. Reflection of waves This applies to both pulses and periodic waves, although it's easier to see for pulses.

This is shown in the diagram below for two downward displaced pulses. In this case, a sine pulse with a maximum displacement of -1 unit negative means a downward displacement interferes with a sine pulse with a maximum displacement of -1 unit.

These two pulses are drawn in red and blue. The resulting shape of the medium is a sine pulse with a maximum displacement of -2 units. Destructive Interference Destructive interference is a type of interference that occurs at any location along the medium where the two interfering waves have a displacement in the opposite direction.

This is depicted in the diagram below. In the diagram above, the interfering pulses have the same maximum displacement but in opposite directions.

### Interference of Waves

The result is that the two pulses completely destroy each other when they are completely overlapped. At the instant of complete overlap, there is no resulting displacement of the particles of the medium.

This "destruction" is not a permanent condition. In fact, to say that the two waves destroy each other can be partially misleading. When it is said that the two pulses destroy each other, what is meant is that when overlapped, the effect of one of the pulses on the displacement of a given particle of the medium is destroyed or canceled by the effect of the other pulse.

## Interference of Waves

Recall from Lesson 1 that waves transport energy through a medium by means of each individual particle pulling upon its nearest neighbor. When two pulses with opposite displacements i.

Once the two pulses pass through each other, there is still an upward displaced pulse and a downward displaced pulse heading in the same direction that they were heading before the interference.