Sensitivity of a balance
Applying slightly different masses on the two pans of the balance, the student can evaluate the lowest mass that the balance can measure.
What students learn
- To understand the principle of balance
- To study the sensitivity of the balance
The science behind this experiment
Balance sensitivity is not a constant. For example, a mass m of nearly 310 mg loaded against a mass M of 10 g produces a shift of 3 divisions, so for a weight of 10 g the sensitivity is 3/310 = 0.01 divisions per mg.
Equipment used
- Scale pan hooked with metal suspension — MEC-031
- Mass 100, 50, 20, 10, 5, 2, 1, 0.5 and 0.3g — MEC-006, MEC-007, MEC-008, MEC-009, MEC-010, MEC-011, MEC-012, MEC-013, MEC-014
- Rod with threaded stem M3, diam. 8 mm, length 70 mm — MEC-041
- “S” hooks, length 30 mm — MEC-032
- Double side scale, silk screen printed — MEC-002
Questions for students
- What is the total force momentum at equilibrium?
- What is the physical meaning of the sensitivity of a balance?
What to expect
This is an example of how to collect the data. Find the equilibrium position when you load two masses to the balance's pans, and experimentally verify the alignment of the pointer at the center of the graduated scale.
Run this experiment in your classroom
This experiment is part of ATP Volta — a self-contained mobile science lab that turns an ordinary classroom into a working STEM laboratory, with over 200 experiments in physics, chemistry, biology, robotics and engineering. Gali, the AI tutor built into ATP Connect, guides students through each step and answers their questions at the bench.
See the ATP Volta mobile science labTalk to our team