The right triangular truss is made of members having equal

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The right triangular truss is made of members having equal cross sectional area of 1550 mm² and Young’s modulus of 2 × 10⁵ MPa. The horizontal deflection of the joint Q is

1. 2.47 mm
2. 10.25 mm
3. 14.31 mm
4. 15.68 mm

Correct Option: D

∑M_R
= 0 135 × 6 = V_p × 4.5
∴ V_p = 180 kN (↓)
∴ V_R = 180 kN ↑ (for balancing)
At P,

F_PQ = 180 kN
θ = tan^-1 (6/ 4.5)
= 53.13°
∴ F_PQ = 225kN F_ak = 180kN

δH =	∑P.L
	AE

=	1000
	1550 × 2 × 10⁵

(Dividing by 125 to get force in each member for 1 kN force)
we get, δH =15.68 mm