Principle
Two small lead spheres are positioned on a beam, which is freely
suspended on a thin metal wire. At the beginning the large lead
spheres are positioned symmetrically opposite to the small spheres
in that way that the attractive forces are eliminated. There after,
the large spheres are swung so that they are close to the small
spheres. As a consequence of the gravitational attracting force the
beam with the small spheres now moves in a new equilibrium
position, where the attractive forces are equivalent to the force
of the torsion of the wire. The gravitational constant can be
determined from the new equilibrium position.
Benefits
- Compact system
- Simple and quick set-up
- Basic constant in physics easily determined
- Data logging via USB
Tasks
- Calibration of an angular detector.
- Determination of the oscillation time of a free and damped
oscillating torsion pendulum.
- Determination of the gravitational constant.
What you can learn about
- Law of gravitation
- Free, damped, forced and torsional oscillations
- Moment of inertia of spheres and rods
- Steiner's theorem
- Shear modulus