Finding the centroid of a shape like a circle or square is very easy. However for an object such as a beam, the centroid is only represented by the geometric center if the material is uniform or homogenous. Beams and other materials are often reinforced with a different material. Such reinforcement likely changes the location of the centroid from the geometric center. It is important that engineers account for this in their designs. Equipment . . . Corkboard or bulletin board Card Stock Paper -8.5" x 11" Scissors 18 in. of string 2. Procedure In this activity you will identify the centroid location of common and complex shapes using object symmetry, mathematics, and MDSolids software. Calculate and Label the Centroid Location 3. Calculate, label, and dimension the X and Y components. Indicate the location of the centroid using the symbol 0.75 in. 0.5 in. 0.50 in. 1-washer, nut, or small symmetrical weight Thumb tack or push pin 1 in. . Ruler Formula(s) Formula(s) Substitute / Solve Final Answer Substitute/Solve I Final Answer Engineering Il-Activity 2.1.1 Centroids- Page 1 *** 3. Engineering II - Activity 2.1.1 Centroids - Page 1 Find the Centroid of a Beam Cross Section a) Determine the overall dimensions of the card stock available to you. b) Using an 8 x 11 card stock paper and draw the "T" shape. c) Cut out the shape and identify any three points on the perimeter of the shape. d) Tie the weight to one end of the string. Tie a loop in the other end of the string to create a plumb bob (a weighted string). e) Attach the shape to a bulletin board with the push-pin or thumb tack (the shape can freely swing) through one of the previously identified points located on the perimeter of the shape. f) Hang the plumb bob from the push-pin or thumb tack (the shape still must be able to freely swing). h) 8.50 3.00-3.25 T 8.0 g) Once the plumb bob stops swaying, mark a line on the shape along the path of the string. Repeat the previous three steps using the two remaining points on the perimeter of the shape. Now, take a photo of the shape with your created 3 lines that intersect at a point. This will be submitted with your assignment. i) The centroid of the shape exists where the three lines intersect. Determine whether the shape will balance on your finger at the intersection. If it does, you have verified the centroid of the shape. j) Measure the distance from the bottom of the shape to the centroid and then from the left edge of the shape to the centroid. Record those values and