# Introduction When we walk along the beach, we often notice that the water level rises and recedes

2500 WordsApr 23, 201910 Pages
Introduction When we walk along the beach, we often notice that the water level rises and recedes at certain times during the day which are known as low and high tides. These high and low tides that we observe on the beaches are caused by waves that form out far out in the ocean that travel along and crash into our coastline. If you have been to the beach more than once, you probably noticed that the high and low tides doesn’t always happen at the same time each day; they change. These waves are caused by an attractive force between masses called gravity and the many objects that contain mass in our solar system are always moving. Because the Moon is constantly orbiting Earth and the Earth is orbiting the Sun, the gravitational forces…show more content…
This is the case with the Sun and our Moon. Although our Sun is 27 million times larger than our Moon, it is also 390 times further away from Earth as compared with the Moon. Based on mass alone, the Sun's gravitational attraction to Earth should be more than 177 times greater than that of the Moon and tidal generating forces from the Sun should be 27 million times greater than that of the Moon. However, when you factor in distance, the tidal force exerted by the Sun is reduced by 3903 and is about half that of the Moon [1]. Tidal Elongation Inertia also plays a role in tidal motion on our planet. Inertia, by definition, is the tendency of objects to keep moving in a straight line at constant linear velocity and therefore wants to counteract the gravitational attraction between objects in order for the two objects to continue traveling in a straight line as shown in Figure 1 [1]. . Fig 1: Illustration of the effect that gravity and inertia have on the Earth’s bodies of water. Retrieved from: http://oceanservice.noaa.gov/education/kits/tides/tides03_gravity.html The Moon pulls most strongly on the water on the Earth’s surface that is facing it simply because it is the closest. Inertia tries to counteract this, but the gravitational attraction prevails on the “near side” of Earth and causes a tidal bulge. However, on the “far side” of Earth, the side facing away from the Moon, the gravitational attraction is weaker and inertia prevails creating another