(a) Compute the vertical deflection of joint D produced by the 30-kip load in Figure P10.1...

(a) Compute the vertical deflection of joint D produced by the 30-kip load in Figure P10.13. For all bars area =2 in2 and E=9000 kips/in2, (b) Assume that the truss is not loaded. If bar AEis fabricated  in too long, how far to the right must the roller at B be displaced horizontally so that no vertical deflection occurs at joint D?