Question

Value 5 marks) 1. Use the method of joints to solve for the load in member AC of the system shown in Fig.1. 2 m 2 m 20 KN 3.5 m 2 m. Fig. 1 (Value 5 marks)

anybody can help?

Answer 1

The objective is to solve for the load in member A C Now the given figure as shown below The methods of joints requires that we start at a known and work our way back Before all that it's the geometry we have to wrap our heads around we can find the angle that the beam C D makes with the horizontal by dropping a perpendicular from D and connecting to C we get a right triangle there that is 2 m high and 2 m wide C D make an angle 45 degree with the vertical move over to B D Drop a perpendicular on B and a perpendicular to D you get a right triangle whose base is 6 m long and whose height is 2 m Arc tangent of the bottom angle gets us 71.56 degree with the vertical so the angle B D makes with the horizontal must be 90 - 71.56 = 18.44 deg