9/29 - 7th Grade Agenda Learning Objective: Learn the difference between transparent, translucent and opaque materials. Collect: Reading & Notetaking: p. 36- 37 Passback Graded HW, Test & Grade Printout Class Reading: p. 46-50 HW: Reading & Notetaking : p.39 – 40 HW: Signed Grade Printout

Daily Reflection Prompt: Give 5 examples of electromagnetic waves. What is the one difference between all the electromagnetic waves? .

Electromagnetic Wave An electromagnetic wave consists of vibrating electric and magnetic field that move through space at the speed of lig____ ht

What are some examples of electromagnetic waves? Radio Waves TV Signals Microwaves Infrared rays Light Ultraviolet rays X-Ray

How fast do electromagnetic waves travel? It is the fastest thing in the universe 300,000 km per second 186,000 miles per second It takes 8 minutes for light to travel from the sun to the earth It takes 3 million years for light to travel from the nearest galaxy (andromeda) to the earth

Electromagnetic Wavelength

How do we use Radio Waves & Microwaves? Radio & TV signals Microwave Oven Radar MRI Cell phone

Using Microwaves Why do you see sparks you put metal objects in a microwave? Because of the build up of electrical energy in the metal The long wave length of Microwaves can pass right through glass and plastic. That is why microwaves do not heat glass and plastic containers.

Cell phone towers icro ation These towers are placed 1 -2 miles apart in a city They use M______wave to communicate with cell phones They can be used to locate the loc_______ of the caller. icro ation

How do we use Infrared Rays? Conventional Oven Heat Lamps Thermograms

Transparent Materials Transparent material trans_____ most of the light that strike it. mit

Translucent Materials A translucent material sca____ light as it passes through, just as smoke, fog, and clouds scatter light as it passes through the air. tters

Opaque Materials An opaque material refl_____ or absorbs all of the light that strikes it. ects