8th Grade Science Guide

8.2: Physics 3 Dimensions & Progressions

Unit 1

STANDARD ● 8.2.5 Develop and use a model to describe the structure of waves and how they are refected, absorbed, or transmitted through various materials. Emphasize both light and mechanical waves. Examples could include drawings, simulations, and written descriptions of light waves through a prism; mechanical waves through gas vs. liquids vs. solids; or sound waves through different mediums. (MS-PS4-2)

CONCEPTS

SKILLS

● Structure of waves ● Wave refection/absorption/transmission

● Develop a model

LEARNING PROGRESSIONS

● A sound wave has a repeating pattern with a specifc wavelength, frequency, and amplitude. ● A sound wave needs a medium through which it is transmitted. ● When light shines on an object, it is refected, absorbed, or transmitted through the object, depending on the object’s material and the frequency of the light. ● The path that light travels can be traced as straight lines, except at surfaces between different transparent materials (e.g. air and water, air and glass) where light paths bend. ● A wave model of light is useful for explaining brightness, color, and the frequency dependent bending of light at a surface between media. ● Because light can travel through space, it cannot be a matter wave, like sound or water waves.

VOCABULARY

● Refracted ● Medium ● Transparent ● Frequency ● Brightness ● Color

● Amplitude ● SoundWave ● LightWave ● Matter ● Mechanical Wave ● Visible Light

● Ray ● Prism

● Wavelength ● Proportion ● Transmitted ● Refected

POSSIBLE PHENOMENA ● A rainbow can be seen in the sky after rain or in a sprinkler when watering on a sunny day. ● Blue whales can hear blue whale sounds from over 800 kilometers away. The Guinness World Record for the farthest a human voice can be heard is 180 meters (on land). ● Snow melts faster around the base of a tree in the spring forming a ring. ● Bats use echolocation to navigate and hunt. ● An arrow behind a glass of water will fip its position as seen, depending on your point of view. ● Foam is hung on walls to soundproof a room. END OF UNIT COMPETENCY WITH LANGUAGE SUPPORTS ● I can develop a model to show how light waves are refected, absorbed, or transmitted through