Candy Density Lab

Movement of Energy: Types of Mechanical Waves Lab

THIS BELONGS TO:

Group: F ~ G ~ H

Types of Mechanical Waves Lab

BACKGROUND READING:

A ______is a disturbance that moves through matter or space, carrying energy from one place to another.

For example, in a water wave in the ocean, energy is ______by water molecules when the wave crashes onto a rock at the beach. It may look like waves carry matter from one place to another, but that is not true: ______.

Waves are usually produced by something moving back and forth. The two main types of waves that we will study today are called “______waves,” which means that these waves need to travel through matter in order to move their energy between two or more places. (Connection: Think of when we used the word “mechanical before” in weathering)

These waves come in many different ______and ______, and depending on their characteristics, they can carry different types of energy (like light, sounds, radiowaves, etc). We will learn about all of the major types of waves in future lessons, but today will focus on the TWO main types.

There are TWO main types of mechanical waves:

1. ______

1. ______(also sometimes known as longitudinal)

MAJOR WAVE TYPE 1: A ______wave is one type of mechanical wave, where particles move back and forth at ______angles to the direction that the wave travels. Examples of transverse waves are some seismic waves that move through the earth during an earthquake and electromagnetic waves: ______, ______waves, and ______.

MAJOR WAVE TYPE 2: A ______wave is a type of mechanical wave where energy moves along the ______direction that the wave travels. An easy way to think of what a compressional wave looks like is to imagine a spring or slinky stretched out horizontally and then a burst of energy moved down one end. ______waves, waves causing ______and certain types of ______can transfer energy via compressional waves.

The Question

Word bank: shape direction of force …………………….. direction of movement other: ______

What is the effect of the properties (______, ______, ______) of a wave on the type of wave that is formed AND the directionAND speed that the energy travels?

H Hypothesis:

Station 1: IF we observe a wave with ______

______as itsproperties, THEN they will form ______type of waves BECAUSE ______.

Station 2: IF we observe a wave with ______

______as their properties, THEN they will form ______type of waves BECAUSE ______.

Station 3: IF we observe a wave with ______

______as its properties, THEN they will form ______type of waves BECAUSE ______.

Station 4: IF we observe a wave with ______

______as its properties, THEN they will form ______type of waves BECAUSE ______.

Variables:

Materials:

Slinky

Colored pencils

Tape

PROCEDURE:

STATION ONE [first three steps are already completed for you]

1. Cut a piece of transparent tape 32cm long.

2. Place two tables about 24 inches apart and stretch the tape between them.

3. Stick pencils to the bottom of the tape, 2cm apart, so they are horizontal in reference to the floor.

4. Tap the tip of ONE pencil at ONE end of the tape. This should produce a wave that travels to the end and reflects back. When a wave hits a boundary between media, all or some of the wave bounces back into the first medium. This is reflection.

5. Do three trials tapping one end of the pencil. TIME how long (how many seconds) it takes for the wave to reflect back to the original pencil. RECORD on your data table.

6. Sketch what this type of wave looks like on your data table and write any observations.

STATION TWO [first three steps are already completed for you]

1. Cut a piece of transparent tape 32cm long.
2. Place two tables about 24 inches apart and stretch the tape between them.
3. Stick pencils to the bottom of the tape, 2cm apart, so they are horizontal in reference to the floor.
4. Tap the tip of BOTH pencils at BOTH ends of the tape AT THE SAME TIME. This should produce a wave, where something happens halfway through, instead of reflecting back like in station 1.
5. Do three trials tapping one end of the pencil. Write down what happens to the waves, instead of having the waves reflect back to their original end.
6. Sketch what this type of wave looks like on your data table and write any observations.

STATION THREE [first three steps are already completed for you]

1. Cut a piece of transparent tape 32cm long.
2. Stick pencils to the bottom of the tape, 2cm apart, so they are horizontal in reference to the floor.
3. Hang the tape from a table, so that one end is taped to the table and the other is hanging freely.
4. Tap the tip of ONE pencil at the end taped to the table. This should produce a wave that travels to the end and reflects back. When a wave hits a boundary between media, all or some of the wave bounces back into the first medium. This is reflection.
5. Do three trials tapping one end of the pencil. TIME how long (how many seconds) it takes for the wave to reflect back to the original pencil. RECORD on your data table.
6. Sketch what this type of wave looks like on your data table and write any observations.

STATION FOUR

1. Have two people take one end of the slink and stand far enough apart so that the slink is straight and does not droop.
2. Have ONE person push their end of the slink while holding onto the end, trying keep the slinky as straight as possible.
3. Do three trials, passing energy from one end of the slinky to another. TIME how long (how many seconds) it takes for the wave to reflect back to the original person. RECORD on your data table.
4. Sketch what this type of wave looks like on your data table and write any observations.

STATION FIVE HOMEWORK STATION: Reread the background text and do a 3-2-1 note taking half-sheet. (Write three facts, two new things you learned, one question, based off of the text)

• Challenge question, if you finish homework early: How does changing the mass of our pencils affect wave velocity?

• Redo-Station #1, but using straws instead of pencils. How does the speed that the wave reflects change when we use straws vs pencils? Make your own data table to record these 5 trials on a piece of loose-leaf (10pts extra credit

Results

Station 1

Challenge question: What is at least one type of wave in nature that is the type of wave at this station? Cite your evidence with the paragraph # from the reading.

Station 2

Challenge question: What is at least one type of wave in nature that is the type of wave at this station? Cite your evidence with the paragraph # from the reading.

Station 3

Challenge question: What is at least one type of wave in nature that is the type of wave at this station? Cite your evidence with the paragraph # from the reading.

Station 4

Challenge question: What is at least one type of wave in nature that is the type of wave at this station? Cite your evidence with the paragraph # from the reading.

CONCLUSION – write on a sheet of loose-leaf and staple on

• Restate the lab’s question and your hypothesis
• State if your hypothesis were supported or not supported
• Summarize the methods
• Explain what you observed
• Describe any limitations of this model and/or future ideas for futureexperiments

Self and Peer Assessment Performance Rubric

• On-task/did not distract others
• Completed work
• Took detailed observations
• Helped others in group when needed

• On-task/did not distract others
• Completed work
• Took detailed observations
• Helped others in group when needed

• On-task/did not distract others
• Completed work
• Took detailed observations
• Helped others in group when needed

• On-task/did not distract others
• Completed work
• Took detailed observations
• Helped others in group when needed

• On-task/did not distract others
• Completed work
• Took detailed observations
• Helped others in group when needed

• On-task/did not distract others
• Completed work
• Took detailed observations
• Helped others in group when needed

• On-task/did not distract others
• Completed work
• Took detailed observations
• Helped others in group when needed

• On-task/did not distract others
• Completed work
• Took detailed observations
• Helped others in group when needed

______/ 8 pts

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