P1 Quiz

The ❌ system has the star called the Sun at its center. It includes all the objects which travel around the sun in paths called orbits. These objects are different sizes and have different paths.
❌ - eight spherical planets travel around the Sun in near-circular orbits.
❌ - the five known dwarf planets are much smaller than planets. They also travel around the sun in near-circular orbits.
❌ - these are lumpy rocks in near circular orbits.
❌ - these objects have very elongated orbits that stretch far away from the Sun and yet may also approach very near to it.
❌ - these are balls of rock that orbit a planet in near-circular orbits.

Red light has a ❌ wavelength than blue light. This change in colour is caused by the ❌ of light waves, and is called the ❌. Light from nearly all galaxies is redshifted. Light from galaxies further away from us have a ❌ redshift. The amount of redshift depends on the ❌ at which the galaxy is moving away. The further away a galaxy is, the faster it moves away from us.
Since we cannot assume that we have a special place in the Universe, this is evidence for a generally ❌ universe. It suggests that everything is moving away from everything else, like the ❌ of a balloon as it is inflated.

In the centres of many oceans, there are mid-ocean ❌. At these places, the ❌ plates are moving apart. Molten material, known as ❌ from inside the Earth oozes out and solidifies. This movement of the mantle is referred to as ❌ due to heating by the core of the Earth. This process is called seafloor ❌. The typical speed of seafloor spreading is ❌: about 10 cm per year. When the magma oozing out of mid-ocean ridges solidifies into rock, the rock records the ❌ of the Earth’s magnetic field. The Earth’s magnetic field changes with time, and sometimes even ❌ its direction. These changes are ❌ in the rocks. The same ❌ are seen on both sides of the mid-ocean ridges.