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WAVES. http://www.youtube.com/watch?v=JN3BQxSroGs. So what is a wave?. Is it energy? Is it force?. A Wave is a disturbance that transfers energy from one place to another without transferring matter . How is this different from what we know of force?. So what is a wave?.
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So what is a wave? Is it energy? Is it force? A Wave is a disturbance that transfersenergy from one place to another without transferring matter. How is this different from what we know of force?
So what is a wave? Remember what the definition of ENERGY is? ENERGY is the ability to cause CHANGE. How is this different from what we know of force? FORCE is the push or pull on an object. How does this tie into our definition of WAVES?
Vocab Day 1: • wave • Mechanical Wave (2) • Medium • wavelength • frequency • speed • amplitude
So what is a wave? http://www.youtube.com/watch?v=JppViHtLNlc (0-1:25 min)
Mechanical Wave • A wave that can travel only through matter (or medium – the material in which a wave travels) • There are TWO Types: • Transverse • Longitudinal
Different Types of Mechanical Waves Transverse Waves – the disturbance is perpendicular to the direction the wave travels.
Different Types of Mechanical Waves Longitudinal Waves – makes the particles in the medium move parallel to the direction that the waves are traveling. What are compressions and rarefactions? Take a min and look up these terms in your text book (pg 496)
Let’s put it together • Students will be put in pair groups • Students will complete step 1 & 2 of mini-lab in text pg 495. • One student will write down observations using at least two vocab terms • Students will complete step 3 • The other student will then write down the observation using at least two vocab terms. • Student pairs will take a 3’ piece of string and tie a smaller piece of string in the middle of the 3’ piece. • facing each other, each will hold one end. • Student A will move the string up and down while Student B holds the string still. Student A will move the string: • Slow with small up/down movement • Slow with large up/down movement • Fast with small up/down movement • Fast with large up/down movement
Let’s put it together • Pair groups will write down their observations • 1. Which type of movement seemed to have the most energy • 2. Did the bow move with the traverse wave? • 3. Did the bow move with the longitudinal wave?
Vocab Day 2: • wave • reflection • Refraction • diffraction • mechanical waves • electromagnetic waves and properties.
Transverse waves look like a roller coaster track. Periods of hills and valleys traveling in a straight line. The shape of a transverse wave looks like hills and valleys because it travels perpendicularly to the force applied. Parts of a Wave Taverse
Transverse waves look like a roller coaster track. Periods of hills and valleys traveling in a straight line. The shape of a transverse wave looks like hills and valleys because it travels perpendicularly to the force applied. Longitudinal waves look like Slinkies. They look like they bunch up then spread out as they travel. This is because they travel parallel to the force. Parts of a Wave Longitudinal
Transverse waves look like a roller coaster track. Periods of hills and valleys traveling in a straight line. The shape of a transverse wave looks like hills and valleys because it travels perpendicularly to the force applied. Longitudinal waves look like Slinkies. They look like they bunch up then spread out as they travel. This is because they travel parallel to the force. http://www.youtube.com/watch?v=al7sFP4C2TY http://www.youtube.com/watch?v=cfXzwh3KadE
QUIZ: Student A draw and label the parts of a Transverse Wave Student B draw and label the parts of a Longitudinal Wave Switch papers and critique the work. A ________ wave travels through a ________. This is different from an electromagnetic wave because em waves can travel in a _________. How are refraction and diffraction similar? How are they different?