Question

Light year is the unit of:

Answer 1

Hint: In this question, we will see the basic definition of light year. This will directly give us the required answer. Further, we will study the basics of the tropical year. We will also see the basics of planets and the structure of our earth, for our better understanding.

Complete step-by-step answer:
 As we know light years are defined as the distance travelled by light in vacuum in one year.
Also, one light year equals to $9.467 \times {10^{15}}m$
Here, we also know that, for most of the space objects, we use light-years to describe their distance.
Therefore, the light year is the unit of distance.

Additional Information: As we know that, a tropical year is also known as a solar year. A tropical year is the time at which the Sun takes to return to the same position in the cycle of seasons, when seen from Earth.
$1yr = 31556926.0s$
Also, as we know that the solar system consists of stars, the Sun, and everything bound to it by the force of gravity , that are: the planets- Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune, also dwarf planets such as Pluto, dozens of moons and millions of asteroids, comets and meteoroids.
Here, we should also know the structure of our earth. We can say that the structure of the earth is divided into four major components called- the crust, the mantle, the outer core, and the inner core. Each of these layers has a unique chemical composition, physical state, and can impact life on Earth's surface. Now, we also know that movement in the mantle, which is caused by variations in heat from the core, causes the plates to shift, which further can cause earthquakes and volcanic eruptions. Therefore, these earthquakes and volcanic eruptions affect the lives and environment on earth.
Also, here a hot spot is said to be an area on Earth over a mantle plume. Hot spot can also be understood as an area under the rocky outer layer of Earth, called the crust, where magma is hotter than surrounding magma. This magma plume causes melting and thinning of the rocky crust and it also widespread volcanic activity.
Since, there are many advantages and limitations of utilizing energy obtained from the hot spots. The one major advantage of utilizing energy from this hotspot is that the cost of production of electricity is very less compared to other sources of electricity.
Further, one major limitation of utilizing energy from this hotspot is that there are very few commercial sites that use this energy, this source of energy is used only in limited applications.

Note: We should remember the S.I unit of time is second, which is represented s. S.I unit of distance is meter m. Also, one should note that there are different numbers of days in a year of different planets. If we take an example of Mars, as Mars is little slower than Earth and also, farther from the Sun, there are 687 days in a Mars year.