Kepler's Second Law using a centripetal force kit
Practical Activity for 14-16
The simple kit demonstrates the increase in speed with a diminishing radius of orbit.
Apparatus and Materials
For each student or group of students
- Centripetal force kit
Health & Safety and Technical Notes
Ensure that the bungs are securely attached and that each student has sufficient space to whirl the bung safely.
The centripetal forces kit is available from:
- Set the bung whirling around the top of the apparatus.
- Pull on the thread to increase the load.
- Kepler's Second Law states that a planet in its orbit sweeps out equal areas in equal times. The time of orbit of the puck will fall as its radius of orbit decreases.
- You can measure the load by attaching a newton meter to the bottom of the string. As the force on the puck is increased, its orbit gets smaller and its speed increases.