# Civil Engineering - Theory of Structures - Discussion

Discussion Forum : Theory of Structures - Section 1 (Q.No. 17)
17.
The force in BF of the truss shown in given figure, is
4t tension
4t compression
4.5t tension
4.5t compression
zero.
Explanation:
No answer description is available. Let's discuss.
Discussion:
10 comments Page 1 of 1.

Mahesh said:   2 years ago
By equilibrium conditions.

All vertical forces=0,
Va + Vb = 5t, ----> eqn(1).

Vb*2=5*1+4*1,
Vb = 4.5t
Va = 4.5t.
(5)

Sk said:   3 years ago
Thanks everyone for explaining.

Michael said:   3 years ago
Why zero can't be? Explain, please.

Gajanan todeti said:   5 years ago

Nath said:   6 years ago
Here, Assume x as the length of each segment.

Abhi said:   6 years ago
How to consider the length of this? Please explain me in detail.

Manoj paridwal said:   7 years ago
Is sign is - then compression?

If sign positive then tension.

Krunal said:   7 years ago
How to determine it as compression or tension?

P.K. Nayak said:   8 years ago

Vb * 2 = 5 * 1 + 4 * 1.
=> Vb = 4.5T Upward.

Considering joint B
Fbc = 0 & Fbf = 4.5T c.
(2)

Reactions are va+ab = 5t.

Moment at A= 4t*x+5t*x-vb*2x = 0.

So 9t = 2vb.

vb = 4.5t.

So force in compression member BF = 4.5t compression.
(1)