Materials
-A smartphone with phyphox installed
-String
-Bucket
-Water
-String
-Bucket
-Water
Procedure
Activity 1 - Bucket of water in a Vertical Circle
What was the centripetal acceleration at the moment when the water was on the verge of falling out?
Identify the constraint on the physics variable at the moment when the water is on the verge of falling out to explain the value of acceleration.
Activity 2 – Conical Pendulum
Procedure
Tie loops of string vertically and horizontally around your phone to make a. Tie a third string to the intersection of the vertical and horizontal loop.
Hold the other end of the string and swing the phone in a conical pendulum while keeping the speed as constant as possible.
Prediction: How will the period of revolution change depending on the angle of the conical pendulum changes?
In the phyphox app, open “Centripetal Acceleration” and press record and swing in a conical pendulum
Export the data from phyphox. Repeat the experiment for at least 3 or 4 angles.
Questions
Did the results of phyphox change your opinion of the relationship between the period and the angle?
Based on your data, describe the relationship between the period and the angle.
- Work in pairs. Tie a string to a bucket of water before filling the bucket with some water.
- Swing the bucket in a vertical circle and slowly decrease the speed until the water is on the verge of falling out at the top of the circle.
- Predict the value(s) of the centripetal acceleration and speed for an object to stay in circular motion.
- Tape your phone securely to the side of the bucket. Open the phyphox app and repeat the procedure.
- Export the data from phyphox and analyze the results to find the acceleration at the top of the circle as the water is close to falling out.
What was the centripetal acceleration at the moment when the water was on the verge of falling out?
Identify the constraint on the physics variable at the moment when the water is on the verge of falling out to explain the value of acceleration.
Activity 2 – Conical Pendulum
Procedure
Tie loops of string vertically and horizontally around your phone to make a. Tie a third string to the intersection of the vertical and horizontal loop.
Hold the other end of the string and swing the phone in a conical pendulum while keeping the speed as constant as possible.
Prediction: How will the period of revolution change depending on the angle of the conical pendulum changes?
In the phyphox app, open “Centripetal Acceleration” and press record and swing in a conical pendulum
Export the data from phyphox. Repeat the experiment for at least 3 or 4 angles.
Questions
Did the results of phyphox change your opinion of the relationship between the period and the angle?
Based on your data, describe the relationship between the period and the angle.
Connections to BC Physics 12 Curriculum
Big Ideas
Forces can cause circular motion
Content Area
Uniform Circular Motion
Curricular Competencies
Questioning and Predicting
Planning and Conducting
Processing and Analyzing Data and Information
Forces can cause circular motion
Content Area
Uniform Circular Motion
- Measuring the centripetal force and acceleration in both horizontal and vertical circles
Curricular Competencies
Questioning and Predicting
- Make observations aimed at identifying their own questions, including increasingly abstract ones, about the natural world
Planning and Conducting
- Collaboratively and individually plan, select, and use appropriate investigation methods, including field work and lab experiments, to collect reliable data (qualitative and quantitative)
Processing and Analyzing Data and Information
- Seek and analyze patterns, trends, and connections in data, including describing relationships between variables, performing calculations, and identifying inconsistencies
- Construct, analyze, and interpret graphs, models, and/or diagrams
- Use knowledge of scientific concepts to draw conclusions that are consistent with evidence
Helpful Links
Measuring Centripetal Acceleration
Measuring Centripetal Acceleration