 27
 0
Hi..
I've got a problem about moment inertia. I don't understand about looking the distance of centroid (y). I am still confucing about the formula of "y" in Moment Inertia. Can you shows me about the formula of y or if any thread for this before, I am glad to see it too.Thanx's for your help..
I still don't know how to find put y =30 and 35
1. The problem statement, all variables and given/known data
Known : You can see the dimension and the picture in my attachment
Asking: How is to calculate y ?? Is the formula same to all geometry??
2. Relevant equations
I = y dA
3. The attempt at a solution
Cross section
Total Area:  A =>40*60=2400
 y => 30 Why is it 30???
 Ay =>72000
Inside Area:A=> 20*30=600
y =>35 Why is it 35???
 Ay => 21000
1. The problem statement, all variables and given/known data
2. Relevant equations
3. The attempt at a solution
I've got a problem about moment inertia. I don't understand about looking the distance of centroid (y). I am still confucing about the formula of "y" in Moment Inertia. Can you shows me about the formula of y or if any thread for this before, I am glad to see it too.Thanx's for your help..
I still don't know how to find put y =30 and 35
1. The problem statement, all variables and given/known data
Known : You can see the dimension and the picture in my attachment
Asking: How is to calculate y ?? Is the formula same to all geometry??
2. Relevant equations
I = y dA
3. The attempt at a solution
Cross section
Total Area:  A =>40*60=2400
 y => 30 Why is it 30???
 Ay =>72000
Inside Area:A=> 20*30=600
y =>35 Why is it 35???
 Ay => 21000
1. The problem statement, all variables and given/known data
2. Relevant equations
3. The attempt at a solution
Attachments

15.6 KB Views: 73