Question

According to the _________ law of Newton the loadings at the sections must act opposite to the forces applied.

(a) First

(b) Second

(c) Third

(d) Fourth

I got this question in an interview for job.

This intriguing question comes from Internal Forces Developed in Structural Members in division Internal Forces of Engineering Mechanics

Answer 1

Correct answer is (c) Third

The best explanation: As the law state that there is always a reaction to every action applied. Thus if the forces are applied at the section of the beams, i.e. the external forces than there must be reactive forces. And these reactive forces act in opposite directions of the forces which are being applied externally.