Math Problem Statement

A cast iron column is 15 cm outside diameter and 12 cm inside diameter. Calculate the max load it may carry if the compressive stress is not to exceed 80 MN/m2 .

Solution

To calculate the maximum load that the cast iron column can carry, we need to use the following formula for compressive load:

Max Load (P)=σ×A\text{Max Load (P)} = \sigma \times A

Where:

  • σ\sigma is the compressive stress (in N/m2N/m^2),
  • AA is the cross-sectional area of the column.

Step 1: Convert diameters from cm to meters

  • Outside diameter Doutside=15cm=0.15mD_{\text{outside}} = 15 \, \text{cm} = 0.15 \, \text{m}
  • Inside diameter Dinside=12cm=0.12mD_{\text{inside}} = 12 \, \text{cm} = 0.12 \, \text{m}

Step 2: Calculate the cross-sectional area of the hollow column

The cross-sectional area of a hollow cylinder is given by the difference between the areas of the outer and inner circles:

A=π4(Doutside2Dinside2)A = \frac{\pi}{4} \left(D_{\text{outside}}^2 - D_{\text{inside}}^2\right)

Substitute the values:

A=π4(0.1520.122)A = \frac{\pi}{4} \left(0.15^2 - 0.12^2\right) A=π4(0.02250.0144)A = \frac{\pi}{4} \left(0.0225 - 0.0144\right) A=π4×0.0081m2A = \frac{\pi}{4} \times 0.0081 \, \text{m}^2 A=0.0020m2A = 0.0020 \, \text{m}^2

Step 3: Calculate the maximum load

Given that the compressive stress σ=80MN/m2=80×106N/m2\sigma = 80 \, \text{MN/m}^2 = 80 \times 10^6 \, \text{N/m}^2:

P=σ×AP = \sigma \times A P=80×106×0.0020P = 80 \times 10^6 \times 0.0020 P=160,000NP = 160,000 \, \text{N}

Final Answer:

The maximum load the column can carry is 160kN160 \, \text{kN}.

Would you like further details or have any questions?

Here are 5 related questions for further exploration:

  1. How would the load change if the inside diameter increased to 13 cm?
  2. What would be the effect on the load if the compressive stress limit was increased to 100 MN/m²?
  3. How can we calculate the safety factor for the column?
  4. What is the difference in maximum load between a solid column and a hollow one of the same outer diameter?
  5. How would the material properties affect the load-bearing capacity?

Tip: Always check the units before performing calculations to ensure consistency and avoid errors.

Ask a new question for Free

By Image

Drop file here or Click Here to upload

Math Problem Analysis

Mathematical Concepts

Geometry
Stress and Strain
Area Calculation

Formulas

Max Load (P) = σ × A
A = (π/4) × (D_outside^2 - D_inside^2)

Theorems

-

Suitable Grade Level

Grades 10-12