Pulses Wave Building Blocks Pulse A pulse is
Pulses Wave Building Blocks
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.
Pulse Reflection • Pulses reflected by a: • Fixed Point – Pulse is reflected in the opposite direction • Floating Point – Pulse is reflected in the same direction
Changing Mediums • When pulses change mediums they are: – PARTLY TRASMITTED – PARTLY REFLECTED Slow Fast medium (high (low density) to Slow Fast medium (high (low density)
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
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.
Example #1 • How would the following two pulses interfere with one another?
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.
Example #2 • How would the following two pulses interfere with one another?
- Slides: 9