1. Pulses
Wave Building Blocks

2. Pulse
A pulse is a single vibratory disturbance that transfers energy but NOT mass.
Amplitude is the height of a pulse above equilibrium – shows ENERGY
A medium is a continuum of particles of a single type
ex: Water, air, metal rod, etc.
The medium stores then releases energy as pulses travel through it.

3. Pulse Reflection Pulses reflected by a: Fixed Point Floating Point
Pulse is reflected in the opposite direction
Floating Point
Pulse is reflected in the same direction

4. Changing Mediums When pulses change mediums they are:
PARTLY TRASMITTED
PARTLY REFLECTED
Slow medium (high density) to
Fast medium (low density)
Fast medium (low density) to
Slow medium (high density)

5. Interference Pulses that encounter one another in a medium INTERFERE.
Pulse amplitudes are added together using the principle of SUPERPOSITION
Two types of interference:
CONSTRUCTIVE and DESTRUCTIVE

6. Constructive Interference
Occurs when amplitude of two pulses is IN THE SAME DIRECTION
ENERGY of the two pulses is ADDED together to produce a HIGHER AMPLITUDE.

7. Example #1
How would the following two pulses interfere with one another?

8. Destructive Interference
Occurs when pulse amplitudes are IN OPPOSITE DIRECTIONS
ENERGY of the two pulses PARTIALLY or COMPLETELY CANCEL OUT to produce a LOWER AMPLITUDE.

9. Example #2
How would the following two pulses interfere with one another?