3 When light strikes a glass surface it can be both refracted and reflected - Edexcel - GCSE Physics - Question 3 - 2013 - Paper 1

The correct option is D. When the wave enters shallower water, its speed decreases while the direction changes due to refraction.

A refracting telescope consists of two convex lenses: an objective lens and an eyepiece. The objective lens gathers light from distant objects like Jupiter and forms a focused image. The eyepiece then magnifies this image, making it appear larger to the observer. By adjusting the distance between the lenses, we can achieve different magnifications.

Galileo’s observations, including the phases of Venus and the moons of Jupiter, provided evidence that not all celestial bodies orbit the Earth, as proposed by the geocentric model. Specifically, the phases of Venus demonstrated that it orbits the Sun, and the discovery of Jupiter's moons showed that not all objects revolve around Earth, supporting the heliocentric model.

Using the ratio of the time taken for light to travel from the Sun to Earth (500 s) and from the Sun to Jupiter (2100 s), we get:

rac{2100}{500} = 4.2

The distance from the Sun to Jupiter can be calculated as:

$4.2 imes 150 \text{ million km} = 630 \text{ million km}$

Thus, the approximate distance of Jupiter from the Earth is 630 million km.