Warm Up 10-19-15 Welcome back from Fall Break. Did you enjoy your fall break. Write about 3 things that you did over the break. Do you feel ready to start the 2nd Nine Weeks of 7th grade course work? Be prepared to share.
Intervention Closure 10-19-15 What is the average speed of a car that travels 25 miles in a half hour (0.5 hr) ? A. 12.5 mph B. 25 mph C. 50 mph D. 75 mph
Science Warm Up 10-19-15
Homework Due Tuesday Read pages 602-607 in your textbook and answer questions # 1-9 on page 607 (write questions & answers) Due Thursday read pages 608-611 in your textbook and answer questions # 1-6 on page 611 (write questions & answers) Bring textbook to class Tuesday & Wednesday this week!
Topic: Wave Properties GLECompare and contrast the basic parts of a wave. GLEInvestigate the types and fundamental properties of waves. Why Important: What causes objects to move differently under different circumstances?
What is a wave? A wave is a moving vibration that transfers energy through matter or space. 2 types of Waves Mechanical waves are transmitted through a medium, such as air or water. The energy of the wave causes the medium to vibrate. If there is no medium, as is the case in outer space, a mechanical wave will stop moving. Mechanical waves can be either transverse or longitudinal. Electromagnetic waves can transfer energy through both a medium and empty space. Light is an electromagnetic wave. Only transverse
Transverse Particles vibrates perpendicular (at right angles) to the wave travel Electromagnetic & Mechanical
Transverse Wave
Transverse Wave Vocabulary Crest—a crest is the highest point of a transverse wave Trough—a trough is the lowest point of a transverse wave Wavelength—the distance between one wave crest and the next (or between one wave trough and the next). Amplitude—the size of the displacement or change caused by the wave. The distance from the rest position to either the crest of trough of the wave.
Longitudinal Particles vibrates parallel to (in the same direction of) wave travel Example sound waves
Longitudinal Wave
Longitudinal Waves Vocabulary Compression—the area of a longitudinal wave in which the molecules are the most crowded together. Rarefaction—the area of a longitudinal wave in which the molecules are the most spread apart Wavelength—the distance from one point of compression to the next on a longitudinal wave
Other Vocabulary Medium- a physical environment in which a wave travels through Wave Speed- how fast a wave is traveling Wave frequency- the number of wave crests that pass by a point each second; measured in hertz
Water Waves A combination of longitudinal & transverse Animation courtesy of Dr. Dan Russell, Kettering University
Longitudinal Use your Slinky to demonstrate a longitudinal wave: Work with a partner Stretch it out along the table One of you grasp and draw several coils of a stretched Slinky toward yourself Release the coils The other student must hold his or her end of the Slinky still A longitudinal wave pulse will be generated and travel down the length of the Slinky.
Science Closure 10-19-15 A _______ is a repeating disturbance or vibration that transfers or moves energy from place to place without transporting mass. A. force B. vacuum C. wave D. medium
Academic Enrichment closure 10-19-15