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Student name: Date: Unit Level/Mark Unit title Waves and Sound Percentage of term work 117% 1 Part 1: Assessment for Feedback and Grade Waves and Sound This is your first assessment for feedback and a grade. This assessment is worth 17% of your course grade. There are four (4) tasks in this assessment. Task 1: Wave characteristics A standing transverse wave is formed in a string that is 5.0 m long. Both ends of the string are fixed. Eight loops are present in the standing wave. Answer the following questions about the wave. Make sure to show all work clearly. 1. Draw the standing wave. Label one node and one antinode. 2. Find the wavelength of the wave. Fully explain how you found the wavelength. 3. If it takes a wave 0.60 s to travel the length of the string, find the speed of the wave. 4. Find the frequency of the wave.

Observations: L, = 7.4 cm L2 = 22.5 cm Lg = 36.7 cm Questions: a) Use the resonant lengths to do three calculations to find the wavelength. Find the average wavelength and use that in further calculations. b) Using the wave equation, what is the speed of sound in the air column? c) What is the theoretical speed of sound in the room according to the temperature? Task 3: Application of the Doppler Effect a) Write a paragraph explaining what the Doppler Effect is and the different effects it has on the observed frequency when the source of the sound is moving toward an observer ver- sus when it is moving away from an observer. Then, state two ways in which the Doppler Effect is applied to situations in everyday life. You will need to do independent research to find the applications. b) A train on a straight track sounds a 400 Hz horn when passing a parked car on the road. The train is moving at 20 m/s and the temperature is 10°С. Find the apparent frequency of the horn for a person sitting inside the car when the train is approaching and when the train is moving away. Task 4: Reflection of Sound Waves A boat is floating at rest in dense fog near a large cliff. The captain sounds a horn at water level and the sound travels through the salt water (1470 m/s) and the air (340 m/s) simultaneously. The echo in the water (due to the cliff) takes 0.40 s to return. How much additional time will it take for the echo in the air to return?