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WavesChapter 14

Kayla LankfordLogan Skorupa

Santiago Vizcaino

Properties of Waves

Waves- A disturbance that transfers energy from one place to another without matter moving a significant distance

There are many types of waves such as… Longitudinal Transversal Ocean Light Sound Electromagnetic

Longitudinal + Transversal Waves

Transversal Waves- Are waves that travel perpendicular to the disturbances direction. Ex) Ocean and light waves

Longitudinal Waves- Are waves that travel in the same direction as the disturbance. Ex) Sound waves and Earthquakes

General Properties of Waves

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Measuring Waves

Frequency- The number of waves that pass a point in a given amount of time

Period- The time it takes a wavelength to pass a point

Speed = Wavelength X Frequency

S

RadioactivityChapter 23

Radioactivity & Radioactive Decay

Radioactivity – spontaneous change in an unstable nucle

Radioactive decay is commonly know as half-lives

Half-life – is the amount of time it takes for half of the radioactive nuclei to spontaneously loose particles Each element or isotope has a different set half

life When different radioactive elements decay they

change into different elements.

Types of radioactivity

Alpha α– an ionized helium atom is ejected from the nucleus Least dangerous & Most easily absorbed

Beta β– an electron or positron is emitted by the atom

Gamma γ– a pocket of energy constantly decaying Most dangerous & most penetrating

Uses of Radiation

There are many different uses of radiation, the most common uses are…..

Radiometric dating – uses beta rays to determine the age of various items

Chemotherapy – the use of Gamma particles to destroy cancerous cells

Fire alarms – use Alpha rays to detect smoke in the air

Radiation around us!

Practice Problems

1. When light passes from air into glass, do the following quantities increase, decrease, or stay the same?

a) speed

b) frequency

c) wavelength

2. Give an equation that relates the speed, frequency, and

wavelength of a wave.

Practice Problems

1. Describe a use of γ radiation.

2. Describe a use of αradiation.

3. Describe a use of β radiation.