Adopt torsion-pendulum method to measure rigid body’s rotational inertia. By measuring different rigid bodies, research on law between movement of rigid body and it’s weight, mass distribution and axis of a quantity, to verify the parallel-axis theorem.
1.Measuring the twist constant of instrument
2.Measuring rotational inertia of plastic cylinder, metallic cylinder, globoid and metal bar.
3.Verify the parallel-axis theorem by changing the position of sliding block on the metal bar.
1.The instrument use steel structure, using three feet nut stent to adjust the horizontal height, fixing the spirit level on the stent.
2.Standard configuration of different kinds of rigid bodies: cylinder, metal hollow cylinders, globe and metal bar with sliding block.
3. Adopt new SCM to control system for the reason of high precision, strong function, stable property and reliable.
4. Equip with millisecond timer and counter.
a) Adopt SCM to control circuits, it can measure the period of object rotation and movement.
b) Automatically save and record multi-group data, and it can calculate the average value precisely.
c) It can be used as general purpose timer, user can master it by membrane switch on the panel and preset by nixie tube to manage the data.
Tester of rotational inertia(millisecond timing counter)
Timing function: five LED digital display, timing at 999.99ms
Counting function:0-30 setting randomly, it can be used as query, save and time.
plastic cylinder(X2),metal cylinder, nylon ball and metal bar
The relative error
Typical experimental context and data
1. Two terminal method
1. Measuring the torsion constant of torsional pendulum “K”
2. Measuring the rotational inertia of plastic cylinder, metal cylinder, nylon ball and metal bar
3. Change the position of sliding block on the metal bar to verify parallel-axis theorem of rotational inertia
Known: experimental value of rotational inertia by tumbler bearing):I’0 = 0.179 x 10-4 kg•m2,
experimental value of rotational inertia by fixture center in metal bar):I”0 = 0.232 x 10-4 kg•m2,
theoretical value of rotational inertia by sliding block around centroidal axis):0.3719 x 10-4 (kg•m2)