Catch the Wave!

Activity 1: How do waves travel? Point of disturbance

Activity 1: Floating Duck DUCKS MOVEMENT WAVES MOVEMENT WAVES MOVEMENT

Activity 4: Cannonball

Activity 4: Cannonball The middle marbles do not move, the flicked marble and the last marbles move. The first marble transferred energy to each of the other marbles. The last marble had no opposing force to stop its motion.

What is happening? SOLID: MARBLES! Energy is transferred from the 1st marble through the other marbles to the last one. What is the medium this energy is traveling through? You saw that energy travels, the marbles do not! How is this similar to a wave moving through the water? SOLID: MARBLES!

Do the water molecules travel across the bin with the wave or do they stay in one place like the duck? The water molecules do not travel across the bin. A disturbance vibrates one molecule and that molecule disturbs another, and the energy is transferred.

WHAT IS A WAVE? A wave is a disturbance that transfers energy from place to place.

WHAT IS A MEDIUM? WATER Any material through which a wave can travel. What was the medium in activity 1? WATER

WHAT MATERIALS CAN ACT AS MEDIUMS? SOLID LIQUID GAS A medium can be anything that has: __________ MASS

WHAT KINDS OF WAVES REQUIRE A MEDIUM? A mechanical wave is a disturbance that travels through the medium of the wave. A mechanical wave requires a medium.

WHAT CREATES WAVES? Waves are created when a source of energy causes a medium to vibrate.

ENERGY MEDIUM MEDIUM DISTURBANCE WAVE WAVE EXAMPLE: A boat propeller A moving object has ______________ A spinning propeller has energy ENERGY A moving object transfers energy to a ______________ when a disturbance is created. The propeller hits the _____________ causing a _______________. This transfers energy from the propeller to the water. MEDIUM MEDIUM DISTURBANCE A ______________ is created WAVE The propeller produces a ____________ that travels through the water. WAVE

BACK TO THE ACTIVITY… YOU! TAPPING THE PENCIL! What caused the disturbance that formed the waves in the bin? YOU! TAPPING THE PENCIL!

WHAT DIRECTION DID THE WAVES TRAVEL? The waves traveled in all directions from the point of disturbance.

WHY DID THE DUCK JUST BOB UP AND DOWN AND NOT TRAVEL ACROSS THE BIN? The energy was transferred from molecule to molecule. So the wave, or energy, travels through the medium. The wave does not carry the medium.

WAVES TRANSFER ENERGY THROUGH THE WATER. WAVES TRAVEL THROUGH THE WATER, BUT THEY DO NOT CARRY WATER WITH THEM. WAVES TRANSFER ENERGY THROUGH THE WATER.

TYPES OF WAVES MOVE Waves are categorized by how they THREE TYPES OF WAVES: MOVE TRANSVERSE LONGITUDINAL SURFACE

TRANSVERSE WAVES DIRECTION OF MOTION

GUIDED READING… Transverse waves move the medium at to the direction in which the waves are traveling. Transverse means Transverse waves move in direction. High parts of the wave are called Low parts of the wave are called RIGHT ANGLES ACROSS ONE CRESTS TROUGHS

Label these parts on (crest and trough) your slinky diagrams from Activity 2. CRESTS TROUGH DIRECTION OF MOTION

Longitudinal Waves (Compression Waves) DIRECTION OF MOTION DIRECTION OF MOTION

Longitudinal Waves (Compression Waves) The energy travels through the slinky. Compression: The part of a longitudinal wave where the particles of the medium are close together Rarefaction: The part of a longitudinal wave where the particles of the medium are far apart

GUIDED READING… Longitudinal waves move the particles in a medium ______________________ to the direction the wave is traveling. Parts of a longitudinal wave that are close together are called ________________________. Parts where the coils are spread out are called __________________________. PARALLEL COMPRESSIONS RAREFACTIONS

BACK TO ACTIVITY 3 COMPRESSION RAREFACTION

SURFACE WAVES Surface waves are a combination of and When do these waves occur? TRANSVERSE LONGITUDINAL THESE WAVES OCCUR WHEN A WAVE CHANGES MEDIUMS.

Surface Wave

Gnarly

WAVE PEAK: PROPERTIES OF WAVES AMPLITUDE (HEIGHT) WAVELENGTH (DISTANCE) FREQUENCY (HOW OFTEN) TIME

AMPLITUDE & WAVELENGTH Low Medium High WAVELENGTH

WAVE PROPERTIES 1. CREST 3. WAVELENGTH 2. AMPLITUDE 4. TROUGH 1 3 2 4 TRANSVERSE WAVE 1 3 2 4 1. CREST 3. WAVELENGTH 2. AMPLITUDE 4. TROUGH

FREQUENCY To increase the frequency of a wave, the wave needs to occur more often in a certain amount of time.

FREQUENCY CALCULATIONS Frequency = Speed ÷ Wavelength F = _____________ ÷ _______________ Frequency = _________________ Hz 6 m/s 2 m 3

5mm 2 Hz 10 FREQUENCY CALCULATIONS S = _____________ X _______________ Speed = Wavelength X Frequency S = _____________ X _______________ Speed = _________________ mm/s 5mm 2 Hz 10

FREQUENCY CALCULATIONS Frequency = Speed ÷ Wavelength F = _____________ ÷ _______________ Frequency = _________________ Hz 50 cm/s 10 cm 5

3 m 6 Hz 18 FREQUENCY CALCULATIONS S = _____________ X _______________ Speed = Wavelength X Frequency S = _____________ X _______________ Speed = _________________ mm/s 3 m 6 Hz 18

DRAWING WAVES… A B

DRAWING WAVES… A B

DRAWING WAVES… B A

WAVE PROPERTIES d. B-G 1. Which distance is exactly 1 wavelength? F G H I J 1. Which distance is exactly 1 wavelength? a. A-J b. A-D c. D-F d. B-G e. D-J d. B-G

B-G, E-I, A-F, F-J, D-H WAVE PROPERTIES C D E F G H I J 2. List as many other letter combinations as you can find that also represent 1 wavelength. B-G, E-I, A-F, F-J, D-H

WAVE PROPERTIES D. 8 boxes C D E F G H I J How many units (boxes) measure one wavelength? a. 2 b. 4 c. 6 d. 8 e. 10 D. 8 boxes

a. B- C b. 2 A B C D E F G H I J 4. Which distance is the amplitude? a. B-C b. A-D c. E-G d. E-I e. A-J 5. How many units (boxes) measure the amplitude? a. 1 b. 2 c. 3 d. 4 e. 5 b. 2

d. B, G b. E, I Which letters are the crests? F G H I J d. B, G Which letters are the crests? A,D b. E,I c. H,J d. B, G e. F,H 7. Which letters are the troughs? a. A,D b. E,I c. H,J d. B, G e. F,H b. E, I

A B C D E F G H I J Resting point Crest Trough Wavelength Amplitude

WAVE INTERACTIONS

WAVE INTERACTIONS Reflection is when an object or wave hits a surface through which it cannot pass and bounces back.

1. SURFACE WAVE INTERACTIONS THE LAW OF REFLECTION STATES THAT THE ANGLE OF INCIDENCE EQUALS THE ANGLE OF REFLECTION. 2. INCOMING WAVE 3. 2. 3. REFLECTED WAVE 4. 5. 4. ANGLE OF INCIDENCE 1. 5. ANGLE OF REFLECTION

CHANGES SPEED AND CHANGES DIRECTION ACTIVITY 7: PEARL What happens to the marble as it hits the water? What happens to a wave as it travels from one medium to another? Why do waves bend as they enter a new medium? The bending of waves due to a change in speed is called SLOWS DOWN CHANGES SPEED AND CHANGES DIRECTION SPEED REFRACTION

ACTIVITY 8: CAUGHT INSIDE

BENDS AND THEN SPREAD OUT GUIDED READING… What is happening to waves as they pass though a narrow entrance to a harbor? When a wave passes through a barrier or moves through a hole in a barrier it The bending of waves around the edge of a barrier is known as WAVES ENTER IN AND THEN SPREAD OUT BENDS AND THEN SPREAD OUT DIFFRACTION

CONSTRUCTIVE WAVE INTERFERENCE + interference occurs when waves combine and create a new wave with a larger amplitude and with larger energy.

WAVE INTERFERENCE DESTRUCTIVE + interference occurs when 2 waves combine to make a wave with a smaller amplitude.

VOCAB Wave: disturbance that transfers energy from place to place Amplitude: energy of a wave Wavelength: distance between two parts of a wave Frequency: rate, #/time

Reflection: Bounces Back Refraction: Change Medium = Change Speed Diffraction: Bending Barrier Constructive Interference: Building Bigger Waves Destructive Interference: Butts heads …no or little waves