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Grade 11Mechanics

Q-The edge of a cube is measured using a vernier callipers.[9 divisons on the main scale is equal to 10divisions of vernier scale and one main scale division is 1mm].The main scale division reading is 1- and 1 division of vernier scale was found to be coinciding with the main scale.The mass of the cube is2.736g.calculate the density in g/cm^3 upto correct significant figures.

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13 Years agoGrade 11
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1 Answer

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ApprovedApproved Tutor Answer1 Year ago

To find the density of the cube, we first need to determine its volume using the measurements provided, and then we can calculate the density using the formula: density = mass/volume. Let's break this down step by step.

Step 1: Understanding the Measurements

From the problem, we know that:

  • 9 divisions on the main scale are equal to 10 divisions on the vernier scale.
  • 1 main scale division (MSD) is equal to 1 mm.
  • The main scale reading (MSR) is 1 mm.
  • 1 division of the vernier scale (VSD) coincides with the main scale.

Calculating the Least Count

The least count (LC) of the vernier calipers can be calculated using the formula:

LC = (Value of 1 MSD) - (Value of 1 VSD)

Since 9 MSD = 10 VSD, we can find the value of one VSD:

Value of 1 VSD = (9 MSD) / 10 = 0.9 mm

Now, substituting into the least count formula:

LC = 1 mm - 0.9 mm = 0.1 mm

Step 2: Finding the Total Measurement

Now, we can find the total reading of the cube's edge:

Total Reading = MSR + VSD = 1 mm + 0.9 mm = 1.9 mm

Converting to Centimeters

Since we need the volume in cubic centimeters, we convert the edge length from millimeters to centimeters:

1.9 mm = 1.9 / 10 = 0.19 cm

Step 3: Calculating the Volume of the Cube

The volume (V) of a cube is calculated using the formula:

V = edge length³

Substituting the edge length:

V = (0.19 cm)³ = 0.19 cm × 0.19 cm × 0.19 cm = 0.006859 cm³

Step 4: Calculating the Density

Now that we have the mass of the cube (2.736 g) and its volume (0.006859 cm³), we can calculate the density:

Density = Mass / Volume

Density = 2.736 g / 0.006859 cm³ ≈ 398.5 g/cm³

Significant Figures

When rounding to the correct significant figures, we observe that the mass (2.736 g) has four significant figures, while the volume (0.006859 cm³) has five significant figures. Therefore, we should express the density to four significant figures:

Density ≈ 398.5 g/cm³

Final Result

The density of the cube is approximately 398.5 g/cm³.