State Assessment Review Physical Science S.HS.2B.3.2

wave – a disturbance that carries energy through matter or space –transverse wave – a wave in which particles of the medium move perpendicular to the direction of the wave electromagnetic waves - transverse waves composed of alternating electric and magnetic fields arranged in order of their wavelength and frequency –(low frequency and high wavelength) Radio Waves – Microwaves – Infrared Waves (Heat) – Visible Light (Red, Orange, Yellow, Green, Blue, Indigo, Violet) – Ultraviolet Rays – X Rays – Gamma Rays (high frequency and low wavelength) water waves

–longitudinal wave – a wave in which particles of the medium move parallel to the direction of the wave sound waves

Characteristics of sound waves: –wavelength – the distance from any point on a wave to an identical point on the next wave Different colors on the electromagnetic spectrum correspond to different wavelengths. –frequency – the number of cycles or vibrations per unit of time The pitch of a sound is determined by the frequency of the wave. The higher the frequency, the higher the pitch.

–Doppler Effect – an observed change in the frequency of a wave when the source or the observer is moving »A higher pitch is observed as the objects move closer together because the waves are compressed. »A lower pitch is observed as the objects move away from each other because the waves are spread farther apart.

–wave speed = frequency x wavelength Waves travel faster through solid mediums because the particles of a solid are closer together and slower through gas mediums because their particles are spread farther apart.

Wave Interactions: –reflection – the bouncing of a wave when it meets a surface or boundary light ray – imaginary line running in the direction that the light travels –Smooth surfaces reflect light at the same angle. –Law of Reflection – angle of incidence = angle of reflection –refraction – the bending of waves when they pass from one medium into another because of a change in speed –diffraction – the bending of waves as they pass an edge or a boundary converging lens – (convex) bends light inward, magnifying glass diverging lens – (concave) bends light outward

–interference – the combination of two or more waves of the same frequency that results in a single wave constructive interference – any interference in which waves meet at the same point at the same time and the waves combine so that the resulting wave is bigger than the original wave destructive interference – any interference in which the crest of one wave meets the trough of another wave and the waves combine so the resulting wave is smaller than the largest of the original waves

Questions: –1. Which list of the following colors shows them in order of the shortest wavelength to the longest wavelength? A. blue, green, red, yellow B. red, yellow, green, blue C. blue, green, yellow, red D. yellow, red, green, blue

Questions: –1. Which list of the following colors shows them in order of the shortest wavelength to the longest wavelength? A. blue, green, red, yellow B. red, yellow, green, blue C. blue, green, yellow, red – correct answer D. yellow, red, green, blue

–2. In which of the following media will a sound wave move fastest? A. Air B. Helium gas C. Water D. Iron

–2. In which of the following media will a sound wave move fastest? A. Air B. Helium gas C. Water D. Iron – correct answer

–3. Which of the following is not a true statement about waves? A. In a transverse wave the particles of the medium move perpendicular to the direction of the wave. B. In a longitudinal wave the particles of the medium move parallel to the direction of the wave. C. When the source of a sound wave is moving away from the observer, the frequency is increased. D. A convex lens bends light inward.

–3. Which of the following is not a true statement about waves? A. In a transverse wave the particles of the medium move perpendicular to the direction of the wave. B. In a longitudinal wave the particles of the medium move parallel to the direction of the wave. C. When the source of a sound wave is moving away from the observer, the frequency is increased. – false statement D. A convex lens bends light inward.