Physics Waves Lab SL Introduction: This lab will investigate the properties of mechanical waves such as a longitudinal wave, focusing on the question: Does a change in the frequency of a wave result in a significant and convincing change in the speed of the wave? Hypothesis: Changing the frequency of the wave will not result in a change in speed because the wavelength will change proportionally as in theory. Student Designed Investigation Procedure/ Planning Procedure: 1. Three students would get into a group. 2.
A Slinky would be spread along a table or along the floor and set up as it shows on the diagram above for about 4 meters. 1. For proper data, the length of the floor was measured and marked with a tape. 2. A student would make small waves, while another would time it with a stopwatch until it reaches the other side.
This step would be repeated, however the wave would be bigger or smaller, in order to find out if changing the frequency, the speed would change. 3. With the data recoded for many different waves, the velocity would be compared for all of them. Materials: 1.
Slinky 2. Role-up meter stick 3. Stopwatch 4. Tape 5. Pen/Pencil 6. Three Lab partners Proposal (diagram) of each Trial: Trial 1: Trial 2: Trial 3: Trial 4: Trial 5: Planning: According to theory, as frequency changes, the wavelength will change proportionally; therefore, speed will remain the same.
By following the procedure that our student design recommends, it will successfully control the variables that should not be changed, such as the slinky, its stretch distance, and the temperature, in order to prove the theory above. The independent variable would be the frequency of the wave, which would change in every trial, while the dependent would be time, which would later be used to find the speed of the traveling wave. In order to collect data, two students would hold the slinky while on would make waves, and a third person would measure the time. A table similar to this should be done after collecting data: Trial Frequency Time Speed.
1 An estimation of the number of waves over time. The time it took for the first wave to reach the end. Speed = distance / time 2... (more trials) 5 recommended Data Data Data Calculations: The student should fill the table above, and compare the results. After collection the speed of each wave, a graph should be drawn where the y axis is the speed, and the x axis should be the frequency. Uncertainty: The uncertainty of this lab would be based on the timing of the student, and the distance that was measured for the slinky.
There would also be an uncertainty of measurement, which should be half of the smallest unit used for measuring the distance of the slinky and +- 0. 5 m because the students might have moved their hands while making waves, thus provoking an uncertainty. The meter stick should be taken into consideration, because if a 1-meter stick would be used to measure 4 meters, it would provoke an uncertainty. The correct measuring device should be the one listed in our materials list, a role-up meter stick, which should be sufficient to cover all 4 meters.
The uncertainty for measuring the speed of each trial should be taken in consideration, for it is hard to get the correct value each time, besides, it is difficult to measure and judge the speed of the wave. Therefore the uncertainty of the time should be around +- 0. 5 seconds. Conclusion: This student-designed investigation tries to access the relationship between the frequency of the wave, and the speed of the wave, and tries to prove the theory that frequency does not change the speed of the wave.