bellwork (4/14) what are electromagnetic waves? waves that consists of oscillating electric and...

Bellwork (4/14)

What are electromagnetic waves?

• Waves that consists of oscillating electric and magnetic fields.

Bellwork (4/15)

What is a wave?

• A vibration in which energy undergoes an oscillation.

Bellwork (4/16)

• What is a medium?

• A physical environment through which a wave can travel.

[you will need to crate a title]name and period

4/14/14 to ?

Objectives:

• Identify relationships between frequency and wavelength for waves in a constant medium

• Physically identify the difference between transverse and longitudinal waves

• Compare the speeds of pulses of waves at different lengths

Hypothesis: (Write the questions and answer them.)

1. What do you think will happen to the speed of the slinky wave as you stretch out the slinky?

2. Why do you think this will happen?

Materials:

• Slinky

• Stop watch

• Meter sticks

Procedures Part I - Observations of waves

Draw each of the following:

1. Labeled transverse slinky wave

2. Labeled longitudinal slinky wave

3. (a) High frequency and (b) low frequency transverse wave

4. (a) High frequency and (b) low frequency longitudinal wave

5. (a) High amplitude and (b) low amplitude transverse wave

Procedures: Part II - Wave Speed

1.Stretch the slinky to 0.60 m.

2.Using a stop watch time a “pulse” (longitudinal wave) as it travels from one end to the other.

3.Conduct FIVE trials and record your results in the data table. Try to make all your pulses constant throughout the trials.

4.Repeat step #1-3 in increments of 0.10 m until you reach 1.50 m.

Data: Pulse WavesDistance

(m)Trial 1

(s)Trial 2

(s)Trial 3

(s)Trial 4

(s)Trial 5

(s)Average

Time (s)

0.60  

0.70  

0.80  

0.90  

1.00  

1.10  

1.20  

1.30  

1.40  

1.50  

Calculations and Variables:1. Calculate the average time for the five trials.

2. Calculate ALL of the velocities (ave. time) for each wave pulse. (Show work for one by using a T-charts)

3. Identify all of your variables as independent, dependent and controlled

Graph:• Make an appropriate graph of your results

using length and velocity. (Hint: Independent variable goes on the x- axis!!!)

Questions for Part 1:(Answer in complete sentences.)1. What was the medium that we used in the lab?2. As you increase the frequency of a wave what

happens to the wavelength?3. As you increase the frequency of a wave what

happens to the period?4. In the lab describe how you were able to

produce a transverse wave and a longitudinal wave.

5. What is the difference between a transverse wave and a longitudinal wave?

6. Could we have used a string tied to ring stand for this lab? Explain why or why not.

Conclusion: Part 2 - Needs to be in your own

words in paragraph form, 10 sentences minimum. – Does your data support or contradict your

hypothesis? Use your data and graph and provide specific examples.

– From your data what can you conclude about the time of pulse as you increase the length?

– Give the relationship between the variables from the graphs, calculations and data.

– Identify the areas of the lab responsible for measurable experimental error.

– Draw conclusions from the results that relate to and/or answer the objectives.

Lab Order and Rubric• Title / Objectives _____ / 4• Hypothesis _____ / 4• Materials _____ / 2• Procedures _____ / 5• 8 Sketches _____ / 20 • Data (part 2) _____ / 4• Calculations _____ / 12• Graph _____ / 12• Questions (part 1) _____ / 12• Conclusion (part2) _____ / 20• Order _____ / 5• Total = _____ / 100