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physics.fisikastudycenter.com - Learning the center of mass, How to simplify the center of mass calculations. Sometimes it's usefull enough applying this method but if you do not feel confidence enough to use it, don't use! Some students got wrong answer when using this method but they got the correct one when using the ordinary way.

From above figure, try to find the location of center of mass of that shape, calculate only the x axis location, because we know that y_o must be at 45 cm!

Answer
Our shape above actually cotents two shapes, a square (shape I) and a triangle (shape two). We assume that you don't have difficulties when finding the center of mass of each shape cause our point here is to show the calculations. Here are our data:

Shape I
Area → A₁ = 90 x 90 (don't multiply)
x location → x₁ = 45

Shape II
Area → A₂ = ¹/₂ (90) x 90 = 45 x 90 (don't multiply)
x location → x₂ = 120
Execute, insert the data to center of mass formula:

We have four groups in here. (90⋅90)45 as first group, (90⋅45)120 as the second, (90⋅90) as the third and (90⋅45) as the fourth.

Follow these steps of calculations:
Step 1 : divide each group with 90 (this number depends on the data you have, not always 90, find another number fits your data for another calculation)
Step 2 : divide the rest with 45 (again, you should find a number fits your data in another calculation)
Step 3 : divide the final rest with 3
Step 4 : get your result

Finally, practices make you better so do alot!