Edging Centering Glue
| No items matching your keywords were found. |
Edging Centering Glue
solve this physics problem?
a small disk of radius 2cm has been glued to the edge of a larger disk of radius 4cm so that teh disks lie in the same plane. the disks can be rotated around a perpendicular axis through point O at the center of the larger disk. the disksboth have a uniform density of 1.4*10^3 kg/m^3 and a uniform thikness of 5 mm. what is the rotational inertia of the two-disk assembly about the rotation axis through O?
IF YOU DON'T KNOW PLZ DON'T ANSWER
the answer in the back of the book says 6.16*10^(-5)
R -radius of the big and r -the small
mass per unit area S=1.4*10^3*5*10^-3=7
mass of large=pi*R^2*S=0.0352
similarly,mass of small=0.0088
Assuming that the small disc is arranged in such a way that, its circumference coincides with that of the larger,
then
moment od inertia of the large,I1=0.5MR^2=2.56*10^-5
I of smallabout its center,i2=0.5mr^2=1.76*10^-6
I of small about O,I2=i2+m(R-r)^2 (parallel axis)
I2=5.28*10^-6
total MOI, I=I1+I2
I=2.56*10^-5+1.76*10^-6
I=2.736*10^-5
Infinity Cutting Tools Edge Banding Router Bit Sets, 61-505 & 61-506