Are You Getting Sleepy? 4 days Day 1 Day 2 Day 3 Day 4

21 Are you Getting Sleepy? (1) What is wavelength? Wednesday February 29th, 2012 Warm-up: (all paste- ins go on 21) (1) What is wavelength? (2) What is amplitude? Objective: Students will be able to collect and analyze data in order to explain the relationship among amplitude, wavelength, and frequency Homework: WI Homework 1 – Due Friday Gradesheets DUE today (may be turned in late)

Vocabulary Reference Mechanical Wave A wave that requires a medium through which to travel.

ARE YOU GETTING SLEEPY? Date: Today INBOX From Date: Today Waves have so many parts! Wavelength, frequency, and altitude, I can’t keep it all straight. I think you mean amplitude. We can’t make that mistake when applying for the teen club job. I wonder if there is any connection between the parts and properties of a wave? Let’s look into that. I bet ya we’ll really impress the teen club owners with that answer!!

What Do These Objects Have In Common? They are all pendulums!

Vocabulary Reference Pendulum A pendulum is an object that is attached to a pivot about which it can swing freely.

Copy the pendulum and label on your paper. 21 Copy the pendulum and label on your paper. Length of String (Wavelength) Amplitude Vibration/ Wave One model scientists can use to study waves is a pendulum. A pendulum consists of a body suspended from a fixed support so that it swings freely back and forth under the influence of gravity.

20 The teacher will pull the washer 10 cm to one side and let the washer go. This is pendulum movement. 1. Describe what happened when the teacher let the pendulum go.

Highlight important information about frequency!. Read the Passage. Highlight important information about frequency!. 21 PENDULUM MOTION When the pendulum swings back and forth, the actual swing can be broken down into two parts – the amplitude and the wave (refer to Figure 1 at the beginning of the investigation for a diagram of these parts). The amplitude is the distance that the pendulum swings from the center point. A wave is simply one complete cycle of a pendulum swing from one side to the other and back again. By counting the number of waves that are created in a given amount of time, we can determine the frequency. In this activity, you will investigate the relationship between amplitude and frequency.

20 2. Explain how you can determine the frequency of the wave created by the pendulum. Use information from the passage and complete sentences in your response. You can determine the frequency by… counting the number of waves that are created in a given amount of time.

20 Problem Question: What is the effect of the amplitude of a wave on its frequency? 3. Identify the independent and dependent variables in this investigation. Independent Variable: Amplitude Dependent Variable: Frequency What is going to be changed in this experiment? What are we going to measure or calculate to see if it has changed?

20 4. Predict what will happen to the frequency as you adjust the amplitude. Use prior knowledge to support your response. I predict that if we increase the amplitude, then the frequency will… Increase Decrease Stay the same

23 Are you Getting Sleepy? Thursday March 1st, 2012 Warm-up: * Please answer in COMPLETE SENTENCES* (1) Describe the relationship between amplitude and frequency. (what YOU predict) Objective: Students will be able to collect and analyze data in order to explain the relationship among amplitude, wavelength, and frequency Homework: WI Homework 1 – Due Friday Gradesheets (may be turned in late)

Notes on Relationships… No not that type… 4 Notes on Relationships… No not that type… Add the following information to page 4 of your notebook. It will be a reference for our investigations in this class. Notes on Relationships Direct relationship: Increase/ increase -decrease/ decrease Inverse relationship: increase /decrease - decrease/increase No relationship No effect on each other

Problem Question: What is the effect of the amplitude of a wave on its frequency? Pre-Lab Discussion: How will we change the amplitude in the investigation? How will we measure the frequency?

Read the procedures “Manipulating Amplitude” A. Measure and raise the washer 5 cm to the right side from the point where your pendulum hangs straight down. B. Release the washer and count the number of complete wave the pendulum makes in 10 seconds. You may want to practice before actually completing this step. **Remember that a complete wave is when the pendulum swings from one side to the other and BACK to the original side. C. Record the number of complete waves or waves in Chart 1, “Amplitude and Frequency.” D. Repeat steps a-c two more times. E. Adjust the amplitude to 10 cm by raising the washer. F. Complete steps b-d for this new height. G. Adjust the amplitude to 20 cm. H. Complete steps b-d for this new height.

CHART 1 AMPLITUDE AND FREQUENCY 21 CHART 1 AMPLITUDE AND FREQUENCY AMPLITUDE --------------- TRIAL 1 TRIAL 2 TRIAL 3 5 cm 10 cm 20 cm NUMBER OF WAVES IN 10 SECONDS (FREQUENCY)

Write your conclusion on page 22 for today’s investigation. 1.The problem question being investigated is “what is the effect of the_____________ of a wave has on its frequency?” 2.My hypothesis is “If the ______________ increased, then the frequency will _____________, because ___________________________________________________. 3.My hypothesis was _____________ (correct/ incorrect). 4.My evidence shows that when the ___________ was ____ cm the frequency was ____ waves in 10 seconds. But when the _____________ was increased to ___ cm the frequency was _____ waves in 10 seconds. 5. This means that _____________________________________

Exit Ticket Answer the following question on the slip. Submit to the bin when dismissed at the end of class. Describe the relationship between amplitude and frequency. Justify your response using information from the investigation. 3 - Answer correctly describes the relationship between amplitude and frequency, and includes a justification from today’s investigation.

25 Are you Getting Sleepy? Friday March 2nd, 2012 Warm-up: * Please answer in COMPLETE SENTENCES* (1) What is frequency? Objective: Students will be able to collect and analyze data in order to explain the relationship among amplitude, wavelength, and frequency Homework: Homework 1 DUE TODAY!

25 As you have seen, amplitude has little if any effect on the frequency of a wave. However, amplitude is not the only property of a wave. All waves have a specific wavelength (the distance from any point on a wave to the same point on the next wave). In your pendulum, the length of the string determines the wavelength. But, does wavelength affect frequency?

25 Problem Question: What is the effect of the wavelength of a wave on its frequency? Identify the independent and dependent variables in this investigation. Independent Variable: Wavelength Dependent Variable: Frequency What is going to be changed in this experiment? What are we going to measure or calculate to see if it has changed?

25 Write a hypothesis for the investigation. If the wavelength is decreased then the frequency will increase / decrease / stay the same (pick 1) because explain why you think the frequency will increase or decrease when the wavelength is decreased

Example Hypothesis If the wavelength decreased then the frequency will decrease because the shorter the string the slower the pendulum will move, making the frequency lower.

25 Read the Lab Procedure MANIPULATING WAVELENGTH a. Raise the washer and release it allowing it to swing freely back and forth. *(The amplitude does not matter for this investigation.) b. Count the number of complete cycles that occur in 10 seconds and record on the chart c. Repeat steps a-b two more times. d. Adjust the length of the string to 15 cm and complete 2 more trials. e. Adjust the length of the string to 10 cm and complete 2 more trials. f. Calculate the average number of waves for each wavelength- Record in the Chart! g. Calculate the frequency for 1 second by dividing your average by 10. Record the frequency in Chart 2.

Chart 2: Wavelength & Frequency 25 Wavelength Average Frequency (wave/1 sec) ----------------- Trial 1 Trial 2 Trial 3 --------------- --------- 25cm 15cm 10cm Number Of Waves In 10 Seconds

27 Are you Getting Sleepy? Monday March 5th, 2012 Warm-up: * Please answer in COMPLETE SENTENCES* (1) What is the relationship between amplitude and frequency? (2) What is the relationship between wavelength and frequency? Objective: Students will be able to collect and analyze data in order to explain the relationship among amplitude, wavelength, and frequency Homework: Draw a Wave and label the 5 parts on page 28

Chart 2: Wavelength & Frequency 25 Wavelength Average Frequency (wave/1 sec) ----------------- Trial 1 Trial 2 Trial 3 --------------- --------- 25cm 15cm 10cm Number Of Waves In 10 Seconds

27 Line Graph Construct a line graph to compare the wavelength and the frequency produced in the investigation. The graph should include a title that includes the variables tested, horizontal and vertical axis, axes labeled with appropriate variables and units of measure, axes scaled appropriately, data accurately displayed.

Indirect Relationship: Wavelength & Frequency 24 Note: The amplitude is remains the same! Indirect Relationship: Wavelength & Frequency Short Wavelength More Frequency Long Wavelength Less Frequency

26 Conclusion Write the conclusion for the investigation. In your conclusion paragraph remember to include the problem question being investigated, the hypothesis the scientist made, a statement about the validity of the hypothesis, evidence from the investigation to support the hypothesis, an explanation of the evidence.

Before Exit Ticket Write anything on the back that you still do not understand. You may select from the categories below: Parts of a Wave Relationship between amplitude and frequency Relationship between wavelength and frequency How waves transfer energy

Exit Ticket: Lab Day 2 Answer the following question on the slip. Submit to the bin when dismissed at the end of class. Describe the relationship between wavelength and frequency. Justify your response using information from the investigation. 3- Answer correctly describes the relationship between wavelength and frequency, and includes information from today’s investigation.

Indicator 1: Wave Characteristics Here Big notes like Outlines will go Vocabulary Words that Need to Be Copied Questions Directions / Warm-ups Answers