Falcon Focus• (8-5.6) According to inertia, a moving object, if no forces act on it, will ____.• A. eventually come to rest• B. eventually change direction• C. slow down but never completely stop• D. remain in motion• • (8-5.6) A book sliding across a floor eventually comes to rest because ___.• • A. there are no forces acting on it • B. there are outside forces acting on it• C. of balanced forces• D. of the mass of the book

Essential Question

• (8-5.5) What are the difference between balance an unbalance forces? Give an example of each.

Waves 8-6.8

Electromagnetic Waves

Electromagnetic Waves• Transverse waves without a medium! • (They can travel through empty space)

• Electromagnetic waves travel VERY FAST – around 300,000 kilometres per

second (the speed of light).

At this speed they can go around the world 8 times in one second.

Electromagnetic Spectrum• Electromagnetic waves have a wide range of

wavelengths. The entire range of wavelengths is called the electromagnetic spectrum. The relationship between the wavelength and energy of waves in various parts of the electromagnetic spectrum can be shown as follows:

Notice the wavelength is long (Radio waves) and gets shorter (Gamma Rays)

Electromagnetic Spectrum

RADIO WAVES

• Have the longest wavelengths and

lowest frequencies of all the

electromagnetic waves.

MRI (MAGNETIC RESONACE IMAGING)

Uses Short wave radio waves with a magnet to create an image.

MICROWAVES

• Have the shortest wavelengths and

the highest frequency of the

radio waves.

Used in microwave ovens.• Waves transfer

energy to the water in the food causing them to vibrate which in turn transfers energy in the form of heat to the food.

Visible Light• Visible Light Is the range of electromagnetic

waves that can be detected by the human eye.

• The entire range of visible light is called the visible light spectrum (ROY G BIV)

• The wavelengths of visible light are in the middle range of wavelengths/frequencies of electromagnetic waves

• The longer the wavelength, the lower the energy of the wave

The Human Eye and Visible Light• The human eye reacts to different energies and

frequencies of light so that different colors are seen

• Higher frequencies (shorter wavelengths) are perceived as colors toward the blue-violet range and have higher energy

• Lower frequencies (longer wavelengths) are perceived as colors toward the orange-red range and have lower energy

VISIBLE LIGHT• Shorter wavelength and

higher frequency than infrared rays.

• Electromagnetic waves we can see.

• Longest wavelength= red light

• Shortest wavelength= violet (purple) light

Infrared Radiation• Infrared Waves (heat)Is the range of

electromagnetic waves with frequencies lower than red on the visible spectrum, thereby having longer wavelengths and less energy than red wavelengths

• All objects emit infrared radiation, and hotter objects emit more infrared radiation than cooler objects

• Heat energy is transmitted by infrared radiation• When objects absorb infrared radiation, they

become warmer

Thermogram—a picture that shows regions of different temperatures in the body. Temperatures are calculated by the

amount of infrared radiation given off.

•Therefore people give off infrared rays.

•Heat lamps give off infrared waves.

Ultraviolet Radiation• Ultraviolet Radiation Is the range of

electromagnetic waves with frequencies higher than violet on the visible spectrum, thereby having shorter wavelengths and more energy than violet wavelengths

• Because of the high energy of ultraviolet radiation, too much exposure is damaging to the eyes and skin

• Used to kill bacteria.

(Sterilization of equipment)

• Too much can cause skin cancer.• Use sun block to protect against (UV

rays)

• Causes your skin to produce

vitamin D (good for teeth

and bones)

X- RAYS• Shorter

wavelength and higher frequency

than UV-rays• Carry a great

amount of energy• Can penetrate

most matter.

Bones and teeth absorb x-rays. (The light part of an x-ray image indicates a place where the x-ray was absorbed)

Too much exposure can cause cancer

(lead vest at dentist protects organs from

unnecessary exposure)

• Used by engineers to check for tiny cracks in structures.– The rays pass

through the cracks and the cracks appear dark on film.

GAMMA RAYS

• Shorter wavelength and higher frequency than X-

rays• Carry the greatest amount of energy and

penetrate the most.

• The Incredible Hulk was the

victim of gamma radiation.

Exploding nuclear

weapons emit gamma rays.

Create the Following ChartElectromagnetic Waves Facts Examples

Radio waves (Real) Radio Waves sends Signals Radio, TV Reception, MRI, Satellite Dish, Car Radio, CB Radio, & Radio Tower

Microwaves (Men) Can be used to send a microwave communication and to cook

Disk-like antennas on tower and a Microwave

Infrared (In) Keep food hot, Communicate with TV, or anything that produce heat

Lamps, Remote Control, Vegetation (trees, grass),

Visible Light (Roy-G-Biv)(Violet)

Anything with colors Rainbow, pictures, & etc…

Ultraviolet Rays (Underwear Are) Tan our skin and comes from the Sun Tanning Salon, UV Rays from the Sun

X-Ray (Extremely) Used to study bones and treat Cancer X-Ray and Stars

Gamma Rays (Gorgeous) Is given off by nuclear explosions that occur within stars, like our sun & Kills Sick Cells and Bacteria/Sterilize Equipments

Stars and Nuclear Explosion

• Electromagnetic Spectrum—name for the range of electromagnetic waves when placed in order of increasing frequency

RADIO WAVES

MICROWAVES

INFRARED RAYS

VISIBLE LIGHT

ULTRAVIOLET RAYS

X-RAYS

GAMMA RAYS

Waves Town Activity

• Brief SUMMARY• A. All electromagnetic waves travel at the same

speed. (300,000,000 meters/second) in a vacuum.

• B. They all have different wavelengths and different frequencies.– Long wavelength-lowest frequency– Short wavelength highest frequency– The higher the frequency the higher the energy.

Falcon Focus

• (8-6.2) Which are mechanical waves?• A. light waves• B. Microwaves• C. Sound waves• D. Radio waves• • (8-6.2) A ___ wave can travel in the absence of matter.• A. light • B. sound• C. seismic• D. water

Essential Question

• (8-5) How would you explain how gravity and friction affects objects?

Create the Following chart

Color of Light Colors ReflectedWhiteRedBlueGreenBlack YellowClear

Chart Conclusion

• 1st: Explain what do you know about reflection and absorption of colors of light.• 2nd: Give an conclusion base on

the results of your data or what you observed.

Falcon Focus

• (8-6.3) In the diagram (pg. 67) in which position would the fish appear to someone looking at if from above the surface of the water?

• • A. A• B. B• C. C• D. D

Essential Question

• (8-6.1) What is a wave and how is a wave created?