How a 13-Year-Old Student Can Find the Mass and Density of an Irregular Solid Using a Spring Balance

Finding the Mass of the Irregular Solid

1. Understanding the spring balance: A spring balance measures the force (in newtons) due to the weight of an object. Weight (W) is related to mass (m) by the formula: W = m × g, where g is the acceleration due to gravity (10 m/s² here).

2. Measure the weight: Attach the irregular solid to the spring balance carefully. Read the value shown on the scale; this is the weight of the object in newtons.

3. Calculate the mass: Since W = m × g, rearrange the formula to find mass:
m = W / g.
Use the weight you read from the spring balance and divide it by 10 m/s² (acceleration due to gravity) to find mass in kilograms.

Finding the Density of the Irregular Solid

Density is defined as mass divided by volume:
Density = Mass / Volume

You already have the mass from the previous step. Now, you need to find the volume of the irregular solid.

1. Measure volume by water displacement:

• Fill a measuring cylinder with some water and note the initial water level (volume).
• Carefully immerse the irregular solid completely in the water without spilling any water outside the cylinder.
• Note the new water level (volume) with the solid submerged.
• The volume of the object is the difference between the final and initial water levels.

2. Calculate density: Now, use the mass you found earlier and divide it by the volume measured by water displacement. The result gives the density in kilograms per cubic meter (kg/m³). If volume is measured in cm³, convert it to m³ by dividing by 1,000,000 (since 1 m³ = 1,000,000 cm³).

Summary:

1. Use the spring balance to get weight in newtons.
2. Calculate mass by dividing the weight by 10 m/s².
3. Find volume by the water displacement method.
4. Calculate density by dividing the mass by the volume.

This method helps you find both the mass and density of any irregular solid object safely and accurately.