| Aim | To measure the mass of two different objects using a beam balance To calculate the percentage error in the measurement of mass |
| Apparatus Required | Beam balance Two different objects of unknown mass Known masses (e.g., 50 g, 100 g, 200 g) Weighing boat Forceps |
| Theory | The beam balance is a widely used laboratory equipment for measuring the mass of different objects. The principle of the beam balance is based on the comparison of the unknown mass with known masses placed on the other side of the beam. In this experiment, we will use a beam balance to determine the mass of two different objects. The beam balance is a laboratory equipment used for measuring the mass of an object. The principle of operation of the beam balance is based on the law of moments, which states that if two forces act on a lever or beam, the moments of the forces are equal if the beam is in equilibrium. In the beam balance, the unknown mass is placed on one side of the beam, while the known masses are placed on the other side. The sliding weight on the beam is adjusted until the beam is balanced. The mass of the unknown object is then determined by summing the masses of the known weights used to balance the beam. To determine the mass of two different objects using a beam balance, we first need to calibrate the balance by weighing the weighing boat and forceps together. This calibration allows us to subtract the mass of the weighing boat and forceps from the total mass of the object and obtain the mass of the object alone. In the experiment, we use forceps to handle the objects and avoid introducing errors due to the mass of our hands. We use known masses, such as 50 g, 100 g, and 200 g, to balance the beam and determine the mass of the unknown objects. The sliding weight on the beam balance is adjusted until the beam is balanced, and the mass of the unknown object is recorded. We repeat the procedure for the second object. After obtaining the masses of the two objects, we calculate the percentage error for each measurement using the formula (|measured mass – actual mass| / actual mass) x 100%. The percentage error provides a measure of the accuracy of the measurement, with a lower percentage indicating a more accurate measurement. Sources of error in the experiment include the mass of the forceps and weighing boat, air currents, and variations in the gravitational field. To minimize these errors, we weigh the forceps and weighing boat together and subtract their mass from the total mass of the object. We also ensure that the beam balance is placed on a stable surface and shielded from air currents. In conclusion, the beam balance is a reliable instrument for measuring the mass of objects, and the experiment allows us to determine the mass of two different objects using this instrument. The experiment also allows us to calculate the percentage error in the measurements and evaluate the accuracy and precision of the instrument. |
| Procedure | Weigh the weighing boat and forceps together and record their mass. Place one of the objects on the weighing boat using the forceps. Adjust the sliding weight on the beam balance until the beam is balanced. Record the mass of the object and the known masses used. Repeat steps 2-4 for the second object. Calculate the percentage error for each measurement using the formula: (|measured mass – actual mass| / actual mass) x 100% |
| Observation and Result | Results: Record the masses of the two objects and the known masses used in a table. Calculate the percentage error for each measurement. Discussion: Compare the measured masses with the actual masses of the objects. Discuss the sources of error in the experiment and suggest ways to minimize them. Comment on the precision and accuracy of the beam balance used. Comment on the usefulness of the percentage error as an indicator of the reliability of the measurements. Conclusion: The beam balance is a reliable instrument for measuring the mass of objects. The experiment successfully determined the mass of two different objects and calculated the percentage error in the measurements. The results indicate that the measurements were reasonably accurate and precise. |
