Chapter 1 – Waves 1.1 What are Waves?

I. Essential Question: What Forms Mechanical Waves? What Are the Types of Mechanical Waves?

II. Key Vocabulary Wave: a disturbance involving the transfer of energy from place to place. Energy: the ability to do work Medium: the material through which a wave travels Mechanical waves: waves that require a medium Vibration: repeated back and forth or up and down motion.

II. Key Vocabulary Transverse wave: a wave that vibrates the medium at right angles (perpendicular) to the direction in which the wave travels. Crest: the high point on a transverse wave Trough: the low point on a transverse wave Longitudinal wave: a wave that vibrates the medium in the same direction in which the wave travels.

II. Key Vocabulary Compression: an area in a long. wave in which the coils are close together. Rarefaction: an area in a long. wave in which the coils are spread out. Surface waves: a combination of transverse and longitudinal waves.

III. Key Concepts Gases, liquids, and solids can all be mediums. Mechanical waves form when a source of energy causes a medium to vibrate. The waves made from a moving a rope up and down are transverse waves; a spring is an example of a longitudinal wave.

III. Key Concepts Parts of a transverse wave:

III. Key Concepts Parts of a longitudinal wave:

III. Key Concepts Surface waves travel along a surface that separates two mediums. Example: ocean waves travel between water and air

Chapter 1 – Waves 1.2 Properties of Waves

I. Essential Question: What are the amplitude, wavelength, frequency, and speed of a wave? How are frequency, wavelength, and speed related?

II. Key Vocabulary Amplitude: the maximum distance the medium vibrates from the rest position. Wavelength: the distance between two corresponding parts of a wave. Frequency: the number of waves that pass a given point in a certain amount of time. Hertz: the unit used to measure frequency (number of waves per second) Speed: how far the wave travels in a given amount of time.

III. Key Concepts

III. Key Concepts Amplitude: Height of a wave’s crest depends on it High waves have more energy and more amplitude In transverse waves, it’s the highpoint or low point of the wave; in long. waves it’s how densely compacted the waves are.

III. Key Concepts Amplitude:

III. Key Concepts Wavelength: Transverse waves: distance from crest to crest or trough to trough Longitudinal waves: distance between compressions The closer the waves are together, the higher the frequency.

III. Key Concepts Wavelength:

III. Key Concepts Speed: Light waves travel much faster than sound waves Determined by dividing the distance a wave travels by the time it takes to travel that distance. (speed = distance / time) Temperature, pressure, and type of medium may change the speed that waves travel.

III. Key Concepts Speed = (wavelength)(frequency) Frequency = speed / wavelength Wavelength = speed / frequency

Chapter 1 – Waves 1.3 Interactions of Waves

I. Essential Question: What changes the direction of a wave? What are the two types of wave interference? How do standing waves form?

II. Key Vocabulary Reflection: the bouncing of a wave off of a surface that it cannot pass through. Refraction: the bending of waves due to a change in speed. Diffraction: the bending of a wave or passing through an opening of a barrier. Interference: the interaction between waves that meet

II. Key Vocabulary Constructive interference: when waves combine to form a wave with a larger amplitude Destructive interference: when waves combine to form a wave with a smaller amplitude Standing wave: a wave that appear to stand in one place, but is really two waves interfering as they pass.

II. Key Vocabulary Node: points of zero amplitude formed by destructive interference; evenly spaced. Antinode: points of maximum amplitude of a standing wave; halfway between two nodes. Resonance: an increase in the amplitude of a wave vibration that occurs when external vibrations match an object’s natural frequency.

III. Key Concepts

III. Key Concepts Reflection:

III. Key Concepts Refraction: When a wave enters a new medium, one half enters before the other half, causing a bend. This does not occur if waves enter the new medium at a right angle.

III. Key Concepts Diffraction:

III. Key Concepts Constructive Interference: Waves add their energies together by overlapping their crests/troughs.

III. Key Concepts Standing wave: When a wave and a reflected wave meet one another.

III. Key Concepts Resonance: Most object’s have a natural frequency of vibration. If this is met, it causes even greater oscillations/waves.