Find the height ȳ of the centroid of the T-section above its bottom edge.
Centroid & second moment of area worksheet with answers
A 240 mm × 200 mm plate has a circular hole of diameter 80 mm whose centre is 180 mm from the left edge (at mid-height). Find the distance x̄ of the centroid from the left edge.
A 100 mm × 240 mm plate has a circular hole of diameter 40 mm on its vertical centre line, with its centre 168 mm above the bottom. Find the second moment of area Ix about the horizontal axis through the centroid.
Find the second moment of area Ix of the T-section about the horizontal axis x through its centroid.
The T-section is used as a beam with the flange on top and carries a sagging bending moment of 15 kN·m. Find the bending stress σbottom at the bottom edge.
A welded I-section has a top flange 130 × 18 mm, a web 400 mm high and 10 mm thick, and a bottom flange 290 × 24 mm (width × thickness). Find its second moment of area Ix about the horizontal axis x through its centroid.
Answer key
- 1. ȳ = 97.79 mm
- 2. x̄ = 113 mm
- 3. Ix = 112 × 10⁶ mm⁴
- 4. Ix = 43.1 × 10⁶ mm⁴
- 5. σbottom = 74.51 MPa
- 6. Ix = 395.6 × 10⁶ mm⁴
Full step-by-step solutions: practise this topic on examproblems.com.