Problem 3: Compute the internal forces (normal force, shear force, and bending moment) in the cantilever beam at point C. You will do this problem two different ways and compare your answers (both methods are required). 120 N/m A B 2 m C 4 m Method 1: Use the right side of the beam 1. Compute the intensity of the triangular load at point C. You can use similar triangles or any other method you like. 2. Cut the beam at point C and keep only the right side (i.e. draw a FBD of the section of the beam from C to B). You must show the triangular load in your FBD, and you must show the internal forces with the correct sign convention. Hint: See example 7.2 on page 335 for a very similar problem. 3. Sum forces in the x-direction and y-direction to compute N and V, respectively. 4. Sum moments about the cut (point C) to compute Mc. It is okay to box a negative value since we're dealing with internal forces here. Method 2: Use the left side of the beam 1. First, compute the external reactions at the fixed end using the overall FBD. You need Ay, Ax, and MA. 2. Now cut the beam at point C and keep only the left side (i.e. draw a FBD of the section of the beam from A to C). You must show the distributed load in your FBD, and you must show the internal forces with the correct sign convention. Hint: The internal forces will not have the same orientation as what you drew for Method 1. You must also show the external reactions acting at point A. See figure below. 120 N/m Ax f^ A Show internal forces here MA Ay 2 m 3. Break the trapezoidal load shape into a rectangle and triangle, and compute the area of each. 4. Now you can sum forces in the x-direction and y-direction to compute N. and Vc respectively. 5. Sum moments about the cut (point C) to compute Mc. Again, it is okay to box a negative value since we're dealing with internal forces here. 6. Compare your answers to what you calculated using method 1. If they are the same, do you expect them to be the same? If they are different, do you expect them to be different?