In the figure below there are two equal couples with a magnitude of M 15 kNm and they act in opposite directions while being applied to the channel beam AB. These couples cause the beam to bend in the horizontal plane. Find the following: 1. Stress at point C 2. Stress at point D 3. Stress at point E = 100 mm D 24 mm 30 mm 150 mm E B 24 mm