Circle (11, 1)

Equations:

A = π ⋅ r

2

C = 2 ⋅ π ⋅ r

 

I =

π ⋅ r4

 

 

-----------

 

 

 

 

 

4

J =

π ⋅ r4

Id =

I + A ⋅ d

2

 

-----------

 

 

 

2

 

 

 

 

Example:

Given: r=5_cm, d=1.5_cm.

Solution: C=31.4159_cm, A=78.5398_cm^2, I=4908738.5_mm^4, J=9817477.0_mm^4, Id=6675884.4_mm^4.

Ellipse (11, 2)

Equations:

A = π ⋅ b ⋅ h

C = 2 ⋅ π ⋅

J =

π-----------------⋅ b ⋅ h

⋅ (b2 + h2)

 

4

 

b2 + h2

I =

π ⋅ b ⋅ h3

-----------------2

--------------------4

 

Id = I + A ⋅ d2

Equations: Example:

Given: b=17.85_∝m, h=78.9725_∝in, d=.00000012_ft.

Solution: A=1.1249E–6_cm^2, C=7.9805E–3_cm, I=1.1315E–10_mm^4, J=9.0733E–9_mm^4,

Id=1.1330E–10_mm^4.

5-44 Equation Reference