What internal action(s) causes a beam to curve?Question 1Select one:a.Bending & Axial tension or compressionb.Bendingc.Bending & Sheard.Torsion

The internal actions that cause a beam to curve are bending and shear. Therefore, the correct answer is c. Bending & Shear.

Here's why:

1. Bending: When a straight material (like a beam) is loaded transversely (perpendicular to its length), it bends. This bending is due to the internal stresses that resist the external load.

2. Shear: Shear stress is a force that causes layers of the material to slide against each other in a direction parallel to the force. In a beam, shear forces can cause one part of a beam to go one way, and another part to go a different way, causing the beam to curve.

Axial tension or compression (option a) and torsion (option d) can also deform a beam, but they do not cause it to curve. Axial tension or compression causes a beam to lengthen or shorten, while torsion causes a beam to twist.