Waves
Essential questions Observe and explain that light can be reflected, refracted, and/or absorbed Recognize that light waves, sound waves, and other waves move at different speeds in different materials
Wave speed Different types of waves travel at different speeds The same type of waves travel at different speeds in different materials For example, mechanical waves travel fastest in solids and at higher temperatures and electromagnetic waves travel fastest in empty space
Calculating wave speed Wave speed = frequency x wavelength
Energy conversions Rock falling from a ledge Potential energy to kinetic energy High temperature to a low temperature Heat/thermal energy Making a soccer ball move Mechanical energy to mechanical energy
https://www.brainpop.com/science/energy/rainbows/
Review: the sun’s energy Emits light waves, ultraviolet waves, and infrared waves
https://www.brainpop.com/science/energy/refractionanddiffraction/
Reflection The bouncing of a wave off a surface without absorption.
refraction The change in direction of a wave as it changes speed in moving from one medium to another
Absorption of light The absorption of light occurs when a ray of light strikes a surface. The energy from the light is transferred to the surface material.
https://ed.ted.com/on/dAXT6QMh
https://ed.ted.com/on/bvA64e7w
http://www.3m.co.uk/intl/uk/3Mstreetwise/pupils-reflective-materials.htm
Interaction of light and matter Transparent material allows almost all light that strikes it to pass through and forms a clear image Translucent material allows most of the light that strikes it to pass but forms a blurry image Opaque material does not allow light to pass through it
transmission Transmission is the passage of light through an object
Law of reflection When a wave is reflected from a surface, the angle of reflection is equal to the angle of incidence
interference Interference occurs when waves that overlap combine, forming a new wave
Chapter 9 review
Through which medium would sound waves move most slowly? Air
Through which medium would sound waves move most quickly? Solids
Is light an electromagnetic wave? Yes
Energy carried by an electromagnetic wave What is radiant energy? Energy carried by an electromagnetic wave
Chapter 10 review
Concave mirror
Convex mirror
Concave lens
Convex lens
Concave and convex lens
refraction Occurs when light waves pass from one material to another and change speed
Refract each wavelength a different amount prims Refract each wavelength a different amount
Speed of sound depends on The forces between particles
Speed of sound and temperature increase The speed of a sound wave increases as the temperature of the material increases
Which surfaces produce diffuse reflection of light? Rough surfaces