Question

A rectangular section metal bar has a width of 10 mm and can support maximum compressive stress of 20MPa; determine the minimum breadth of the bar when loaded with a force of 3kN.

Answer 1

The compressive stress on the bar is 300 kPa, and the minimum breadth of the bar when loaded with a force of 3kN is 3000 mm².

Step-by-step explanation:

To determine the minimum breadth of the bar when loaded with a force of 3kN, we need to calculate the compressive stress on the bar and use it to solve for the minimum breadth. Compressive stress is defined as the force acting on an area and can be calculated using the formula:

Stress = Force / Area

In this case, the force is given as 3kN, which is equal to 3000N, and the area is the width of the bar, which is 10 mm or 0.01 m. So the compressive stress is:

Stress = 3000 N / 0.01 m² = 300,000 Pa = 300 kPa

To find the minimum breadth, we can rearrange the formula for stress:

Stress = Force / Area

to:

Area = Force / Stress

Substituting the given values:

Area = 3000 N / 20 MPa = 0.3 m² = 3000 mm²

So, the minimum breadth of the bar when loaded with a force of 3kN is 3000 mm².POST