Question

the sum of all loads and reaction forces acting on a truss needs to be zero.
true
false
question 5
which methods can be used to analyze planar trusses?
choose all that apply
method of joints
method of sections
graphical method
all of the above

Explanation:

First Question (True/False)

For a truss in equilibrium (static equilibrium), the sum of all external forces (loads and reaction forces) must be zero (both in x - and y - directions, and the sum of moments about any point is also zero). This is based on the principles of static equilibrium in engineering (a subfield of Natural Science, specifically related to Physics and Engineering). So the statement "The sum of all loads and reaction forces acting on a truss needs to be zero" is True.

• Method of Joints: This method is used to analyze planar trusses by considering the equilibrium of forces at each joint (applying $\sum F_x = 0$ and $\sum F_y=0$ at each joint).
• Method of Sections: In this method, a section is cut through the truss, and the equilibrium of the resulting free - body diagram (forces and moments) is analyzed.
• Graphical Method: Graphical techniques (like using force polygons) can also be used to analyze the forces in planar trusses, especially for simpler trusses.

Since all three methods (Method of Joints, Method of Sections, and Graphical Method) can be used to analyze planar trusses, the correct option is "All of the above".

Answer:

True

Question 5 (Multiple - Choice)