

Explanation
(i) An eclipse is a shadow that results from the obstruction of light from the sun by the moon or the earth.
(ii) Types of eclipse:
-Eclipse of the sun or solar eclipse.
-Annular eclipse
- Eclipse of the moon or lunar eclipse.
(b i) The eye defect is long sight or hypermetropia.
(ii) The type of lens to correct the defect is convex or converging lens.
(iii) Power of lens = \(\frac{1}{f} = \frac{1}{0.1} = dioptre(D)\)
(c) Velocity of an echo = \(\frac{2d}{t}\)
d = \(\frac{vt}{2} = \frac{340 \times 5 \times 10^{-3}}{2} = 0.952 m\)
(d) M = \(\frac{v}{u}\)
U = \(\frac{V}{M} = \frac{9}{0.6} = 15cm\)
\(\frac{1}{f} = \frac{1}{u} + \frac{1}{v} = \frac{1}{15} + \frac{1}{-9}\)
f = -22.5cm

