The plane truss shown in the figure has 13 joints and 22 members. The truss is made of a homogeneous, prismatic, linearly elastic material. All members have identical axial rigidity. A to M indicate the joints of the truss. The truss has pin supports at joints A and L and roller support at joint K. The truss is subjected to a 10 kN vertically downward force at joint H and a 10 kN horizontal force in the rightward direction at joint B as shown.

The magnitude of the reaction (in kN) at the pin support L is __________ (rounded off to 1 decimal place).

Consider the pin-jointed truss shown in the figure (not to scale). All members have the same axial rigidity, AE. Members QR, RS, and ST have the same length L. Angles QBT, RCT, SDT are all 90°. Angles BQT, CRT, DST are all 30°. The joint T carries a vertical load P. The vertical deflection of joint T is k$\rm \frac{PL}{AE}$. What is the value of k?

An idealised bridge truss is shown in the figure. The force in Member U2L3 is __________ kN (round off to one decimal place).

The members which do not carry any force are