Question

ℏḙℓℓ✺ Պᾰтḙṧ !!


...give full explanation...

❌❌Dont spam❌❌
​

Answer 1

hi pal that is the answer excuse me for my handwriting...

hope it helps

Answer 2

Answer-

$i_{2} - i_{1} = 4 {m}^{2}$

Explanation-

✍.. as the mass is uniformly distributed on the disc,

so,

$mass \: density = \frac{9m}{\pi {r}^{2} }$

and, mass of removed portion=

$\frac{9m\pi}{\pi {r}^{2} } \times \frac{r}{3} {}^{2} = m$

so, the moment of inertia of the removed portion about the stated axis by theorem of parallel axes is,

$i_{1} = \frac{m}{2} \times \frac{r}{3} {}^{2} + m \frac{2r}{3} {}^{2} = \frac{ {m}^{2} }{2} ........(i)$

the moment of inertia of the original complete disc about the stated axis is,

$i_{2} \: then \: \: i_2 = 9m \times \frac{ {r}^{2} }{2} ........(ii)$

so, the moment of inertia of the left over disc is

$i_{2} - i_{1}$

i. e.

$i_{2} - i_{1} = 4m {r}^{2}$

__________________________________