Warm Up 6

• W• A• R• M• U• P

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D. Wave velocity, or v, describes how fast the wave moves forward.

v = f x λVelocity = frequency x wavelength

Example:A water ripple is being

sent across a pool of water by a boat that is rocking at a rate of 1.5 hertz. The ripples are measured to be 2 meters apart. How fast are they moving?

v = f x λv = 1.5Hz x 2mv = 3 m/s

E. Amplitude—a measure of the energy in a wave

The more energy a wave carries, the bigger its amplitude

Which transverse wave has more energy?The bottom wave because it has the biggest amplitude.

III. The Behavior of Waves

What do you do when a wave misbehaves????

Reflection

• Reflection happens when a wave strikes and bounces off an object

• All types of waves can be reflected.

Normal

Angle of incidence

Angle of reflection

The angle of incidence of a wave is always equal to the angle of reflection.

a. Normal - an imaginary line perpendicular to a reflective surface

b. Angle of incidence - the angle formed between the wave and the normal

c. Angle of reflection - the angle formed between the reflected wave and the normal

Refraction—the bending of a wave caused by a change in its speed as it moves from one medium to another

Slower

Faster

Diffraction

1. Diffraction occurs when an object causes a wave to bend

2. Large objects cause more bending3. Small objects cause less bending

DiffractionDiffraction

Interference

A. Occurs when 2 waves interact• Constructive interference—waves

add together• Destructive interference—waves

subtract from each other

Interference

E. Resonance - the ability of an object to vibrate by absorbing energy at its natural frequency

Exit Ticket 4

• If a dog whistle has a frequency of 3.0 x 104 Hz, what is the wavelength of the sound if the speed of sound is 330 m/s?