How Seeing Works

Constructive and Deconstructive Interference

 Constructive Interference is when waves ADD or BUILD. The waves are on the SAME SIDE.

Deconstructive Interference is when waves SUBTRACT or CANCEL each other (temporarily until they're no longer overlapping). The waves are on OPPOSITE SIDES.

You can also have interference with standing waves. Look to see how they're "in sync" or "out of sync" and how that makes them add to be bigger or cancel to be smaller.

Examples:

A (+2) + (+3) wave = +5 wave

A (-2) + (+3) wave = +1 wave

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Sound Waves

 Image of a sound wave traveling through particles.

Sound is when something vibrates and starts to move a medium through compressions. The energy is carried by the particles in the medium. They bump into each other (this is where the compression is) and then bounce back to roughly their starting position. Notice: this is a description of longitudinal.

The ENERGY transfers or is passed along from particle to particle. The particles themselves just move left and right a short ways. Particles don't move across the room.

Labeled Waves

 Waves are a way in which energy is transferred. You can see the energy moving forward. The difference between transverse and longitudinal is the direction the medium travels in relation to the energy.

What are the parts of the wave???

Know these terms:

• Compression
• Crest
• Amplitude
• Wavelength
• Rest position/equilibrium

Calculating Cost of Electricity

Price for electricity is given in $/kWh.

If you'd like to know the cost you follow this formula:

$ = $/kWh * kW *h

OR

$ = $/kWh * kWh

Notice, since the price is given as an amount per 1 kWh, you need to find the total amount of kWhrs then multiply the price by your kWh.

Circuit Symbols

Static Electricity #3: Net Force