The limit of resolution (angular) is $\Delta \theta = \frac{1.22 \lambda}{D}$, where $D$ is the diameter ($2 \times 0.25 = 0.5 \text{ cm} = 0.005 \text{ m}$).

Minimum separation $y = d \cdot \Delta \theta = \frac{1.22 \lambda d}{D}$

$y = \frac{1.22 \times 500 \times 10^{-9} \times 0.25}{0.005} \approx 30.5 \times 10^{-6} \text{ m} = 30.5 \ \mu\text{m}$.

The Holliday-Segar method calculates maintenance fluid requirements:

Calculation for 12 kg child:

\[\text{First 10 kg} = 10 \times 100 = 1000\,\text{mL}\]

\[\text{Next 2 kg} = 2 \times 50 = 100\,\text{mL}\]

\[\text{Total} = 1000 + 100 = 1100\,\text{mL/day}\]

Hourly rate: \(\dfrac{1100}{24} \approx 46\,\text{mL/hr}\)

This formula is essential for pediatric nurses. Remember: it calculates maintenance only — deficit and ongoing losses are added separately in dehydrated children.

Let distance X to Y $= d$. Total distance $= 2d$.

Total time $= \dfrac{d}{v_u} + \dfrac{d}{v_d} = d\cdot\dfrac{v_u + v_d}{v_u v_d}$

Average speed $= \dfrac{2d}{d\cdot\dfrac{v_u+v_d}{v_u v_d}} = \mathbf{\dfrac{2v_u v_d}{v_u + v_d}}$ (harmonic mean)

• Statement B is false because water exhibits extensive intermolecular hydrogen bonding, not intramolecular.
• Intermolecular bonding occurs between different molecules, which is responsible for water's high boiling point and surface tension.