Mechanics problem - centre of mass

AI Thread Summary
The problem involves calculating the center of mass for a system of three uniform rods forming an inverted U shape, with specific masses and lengths. The x-coordinate of the center of mass is determined to be 0.11 m based on the uniform distribution of the rods. However, there is confusion regarding the calculation of the y-coordinate, with no clear examples available in the reference material. The discussion emphasizes the need for a better understanding of the y-coordinate calculation, particularly in visualizing the system from the side. Clarification on these concepts is crucial for the upcoming mechanics examination.
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Homework Statement


Three uniform rods, each of length L = 22cm, form an inverted U. The vertical rods each have a mass of 14g; the horizontal rod has a mass of 42g. What are (a) the x coordinate and (b) the y coordinate of the system's centre of mass?


Homework Equations



x(com) = 1/M \int x dm
y(com) = 1/M \int y dm

dm/M = dx/L
dm/M = dy/L

The Attempt at a Solution



I used the result of the integration done to find that the centre of mass of a uniform rod in terms of its length: x(com) = L/2.

x(com) = 0.22 m / 2 = 0.11 m

However, I've no idea about what the y coordinate of the centre of mass would be. I am completely confused and I cannot find any examples of such a situation in my book. I have a mechanics examination tomorrow and need to clear up any misunderstood concepts so I would greatly appreciate any help.
 
Physics news on Phys.org
Try viewing it from the side.

Pretend you have a 42g object sitting on a see-saw that weighs 28g and is 22 cm long, and they have asked you to find the balance point with no weight at the other end.
 
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