The textbook provides specific details about Pakistan's freedom of information framework:

• President Pervez Musharraf promulgated the Freedom of Information Ordinance 2002 in October 2002
• Response timeframe: Government bodies must respond within 21 days
• Applicable bodies: Federal government bodies including ministries, departments, boards, councils, courts, and tribunals
• Excluded: Government-owned corporations and provincial governments — significant gaps in coverage

Contrast this with India's Right to Information Act (2005): response required within 30 days (or 48 hours for matters concerning life and liberty). The textbook is critical of Pakistan's ordinance, noting that “large amounts of information are also not subject to disclosure under the ordinance, largely undermining the public's right to know” and that its restrictive list of disclosable records further limits its effectiveness. This legal knowledge is essential for journalism students understanding press freedom frameworks.

Using the superposition principle: Potential at cavity centre = (Potential due to full sphere at that point) $-$ (Potential due to removed small sphere at its own centre).

The cavity centre is at distance $R/2$ from the big sphere centre.

Potential due to full sphere at $r = R/2$ (inside):

$V_{full} = -\frac{GM}{2R^3}\left(3R^2 - \frac{R^2}{4}\right) = -\frac{11GM}{8R}$

Potential due to removed sphere (mass $M/8$, radius $R/2$) at its own centre:

$V_{small} = -\frac{3G(M/8)}{2(R/2)} = -\frac{3GM}{8R}$

$V_{cavity} = V_{full} - V_{small} = -\frac{11GM}{8R} + \frac{3GM}{8R} = -\frac{GM}{R}$

Waxes are esters of long-chain fatty acids with long-chain alcohols. Acylglycerols (fats/oils) are esters with glycerol. Phospholipids have a phosphate group.