Two discs one of density 7.2 g/cm^(3) and the other of density 8.9 g/cm^(3) are of same mass and thickness. Their moments of inertia are in the ratio

Two discs one of density 7.2 g/cm^(3) and the other of density 8.9 g/c

1.	Two discs one of density 7.2 g/cm^(3) and the other of density 8.9 g/cm^(3) are of same mass and thickness. Their moments of inertia are in the ratio
Answer» <html><body><p>`8.9 : 7.<a href="https://interviewquestions.tuteehub.com/tag/2-283658" style="font-weight:bold;" target="_blank" title="Click to know more about 2">2</a>`<br/>`7.2 : 8.9`<br/>`(8.9 xx 7.2) : <a href="https://interviewquestions.tuteehub.com/tag/1-256655" style="font-weight:bold;" target="_blank" title="Click to know more about 1">1</a>`<br/>`1 : (8.9 xx 7.2)`</p>Solution :`(I_(1))/(I_(2)) = ((1)/(2) M_(1) r_(1)^(2))/((1)/(2) M_(2 r_(2)^(2))) = (r_(1)^(2))/(r_(2)^(2))` <br/> As masses of two <a href="https://interviewquestions.tuteehub.com/tag/discs-955668" style="font-weight:bold;" target="_blank" title="Click to know more about DISCS">DISCS</a> are equal , hence `(<a href="https://interviewquestions.tuteehub.com/tag/pi-600185" style="font-weight:bold;" target="_blank" title="Click to know more about PI">PI</a> r_(1)^(2) t) rho_(1) = (pi r_(2)^(2) t) rho_(2)` <br/> or `(r_(1)^(2))/(r_(2)^(2)) = (rho_(2))/(rho_(1)) therefore (I_(1))/(I_(2)) = (rho_(2))/(rho_(1)) = (8.9)/(7.2)`</body></html>