Method of joints example 2

The video tutorial demonstrates how to apply the method of joints to solve a challenging truss problem. The goal is to find the internal force in member BC. The process begins with analyzing the geometry of the truss, followed by examining joint A to determine forces AB and AC. The tutorial then moves to joint B, where the forces BD and BC are analyzed. The calculations reveal that member BC is a zero-force member, meaning it has no internal force. The tutorial emphasizes the importance of understanding trigonometry and equilibrium equations in solving such problems.

What is the first step in solving a truss problem using the method of joints?

• Calculate the internal forces

• Choose a joint to analyze

• Analyze the geometry

• Analyze the reaction forces

Why is it unnecessary to analyze the reaction forces in this problem?

• The reaction forces do not affect the internal forces

• The reaction forces are already known

• The reaction forces are negligible

• The problem is too simple

Why is joint A chosen for analysis instead of joint B?

• Joint A is closer to the supports

• Joint B is not part of the truss

• Joint B has too many unknowns initially

• Joint A has fewer unknowns

What is the internal force in member AB after analyzing joint A?

• 0 kN

• 20 kN

• 14.14 kN

• 10 kN

What is the internal force in member AC after analyzing joint A?

• 10 kN

• 20 kN

• 14.14 kN

• 0 kN

What is the internal force in member BD after analyzing joint B?

• 4.14 kN

• 0 kN

• 14.14 kN

• 10 kN

What conclusion is drawn about member BC after analyzing joint B?

• BC is a zero-force member

• BC is under tension

• BC is not part of the truss

• BC is under compression