__Unit 9: Periodic Motion:__ Springs, pendulums, mechanical waves & sound

__Unit 9: Periodic Motion:__

__Reading__

BJU book: Ch. 12 "Periodic Motion"

AP students additional reading: Princeton Review "Oscillations" and "Waves" - read the applicable sections

__Topics__

- Mechanical waves & sound
- Pendulums
- Spring-Mass systems

__Labs__

- Spring-Mass lab
- Pendulum lab

Below: Various ways of depicting periodic motion

__Periodic Motion Lab:__

__In-person lab:__

Write up your lab results from the Pendulum and Spring-Mass experiments. An "Instructor Example" is provided below for guidance, but you must use your own measurements and sketches! Make sure you include all the required items, below.

__Virtual lab:__

If you are doing this lab at home, use the raw data in the "Data Gathering" video below. You need to write-up your lab report just like the "Instructor Example", but using the raw data in the Data Gathering video. Make sure you include all the required items, below.

__Required items:__

Required for your

__pendulum__experiment:

- Labeled sketches and raw data from your pendulum experiment, showing the mass of the pendulum, length of the pendulum arm, the measured period 'T' of your pendulum (taken from your stopwatch measurements).
- Your calculations showing the 'theoretical' period 'T' in seconds of your pendulum, using the pendulum formula T = 2 x pi (l/g)^1/2.
- A comparison of your 'measured' T-value (from stopwatch) to your 'theoretical' T-value, and a calculation of your % error.

__spring-mass__experiment:

- Labeled sketches and raw data from your spring-mass experiment, showing the mass of the plumb-bob, and the measured period 'T' of your spring-mass system (taken from your stopwatch measurements).
- A graph of the restoring force in N (y-axis) versus the spring displacement in m (x-axis) for your spring.
- A computation of the 'slope' of the line in the above graph, which represents 'k', the spring constant, in the formula F = k(delta-x). Remember slope is defined as 'rise over run', or delta-y/delta-x.
- Your calculations showing the 'theoretical' period 'T' in seconds of your spring-mass system, using the formula T = 2 x pi (m/k)^1/2.
- A comparison of your 'measured' T-value (from stopwatch) to your 'theoretical' T-value, and a calculation of your % error.

periodic_motion_lab_report_INSTRUCTOR EXAMPLE |

You can use this engineering_graph_paper_10_per_inch.docx |

"Data Gathering" video with a quick overview of the lab, plus the raw data for the virtual lab:

__Homework__

The Periodic Motion problems are hosted in Canvas. The video below pertains to these problems.