State the precautions taken to ensure accurate measurement when having an experiment using the principle of moment
The correct answer and explanation is:
Correct Answer:
Precautions taken to ensure accurate measurement when performing an experiment using the principle of moments include:
- Use a well-calibrated and balanced beam.
- Ensure the pivot point (fulcrum) is frictionless or has minimal friction.
- Suspend weights vertically using string or hooks.
- Measure distances from the pivot using a ruler with fine graduations.
- Place weights gently to avoid shifting the apparatus.
- Avoid parallax error by reading measurements at eye level.
- Use known standard weights.
- Ensure the system is in static equilibrium before taking readings.
- Repeat measurements and average the results.
- Avoid draughts or vibrations during the experiment.
300-Word Explanation:
The principle of moments states that for a system in equilibrium, the sum of the clockwise moments about a pivot must equal the sum of the anticlockwise moments. To ensure accurate results in an experiment demonstrating this principle, several key precautions must be taken.
Firstly, a balanced and horizontal beam ensures that the initial condition of equilibrium is known and that any moment caused by weights is accurately reflected. The pivot (fulcrum) should be stable and have minimal friction, as excess friction can resist rotation, causing errors in the moment measurement.
When placing weights on the beam, they must be suspended vertically using string or proper hooks so that their force acts vertically downward, as assumed in moment calculations. The distance from the pivot (moment arm) should be measured with precision, using a fine-graduated ruler, and should be taken from the center of mass of each weight.
To avoid parallax error, which occurs when measurements are taken from an angle, readings must be done at eye level. Additionally, using standard, calibrated weights avoids inaccuracies due to unknown or inconsistent mass.
Ensuring that the beam remains in static equilibrium—not moving—when taking readings is crucial to apply the principle correctly. Repeating the measurements and taking an average helps to reduce the influence of random errors.
Finally, the setup should be free from external disturbances such as wind or vibrations, which can introduce noise and instability, affecting the balance.
By following these precautions, one can minimize experimental errors and accurately verify the principle of moments in a laboratory setting.