Zachary CollinsMrs. WillisonEnglish 831 January 2018 The Up and Down Behind A Floating Boat Gravity, Density and Buoyancy are impacts when trying to float a boat. Gravity has a major affect on a boat because its pulls it downwards and a boat needs to float and not sink. Buoyancy is also an impact because it’s the counter of gravity. Gravity pushes down and buoyancy pushes up. Buoyancy is the only reason a boat can float due to a downward force caused by gravity. Buoyancy is the patterns of a object to float when inside a fluid. Buoyancy is caused by a upward pressure from the fluid that goes up against the weight of the item. The Archimedes principal states that the force on the thing is equal to the weight of the liquid being moved by the object. Anything that weighs less than the liquid floats. (Buoyancy) There are three types of buoyant items. there are negatively buoyant items, neutrally buoyant items, and positively buoyant items. An item that sinks in fluid is negatively buoyant. Something that stays where it is in its vertical placement is called a neutrally buoyant item. Any item with buoyant force against it that is strong enough to make the object float is called a positively buoyant item. (How Things Float Online) Density is the mass of an object divided by the volume. Mass is normally measured in kilograms. Volume is measure in cubic meters and cubic centimeters most of the time. Dividing by the volume cancels out the amount of material being used. Density is independent from the amount or size of material. The more density an object has the more this object weighs. Density is based on the weight and the volume combined. (Density Online) Gravity is the force of attraction for all objects because they have mass. Because of gravity anything that is already on earth surface has a downward pull or force on it. Gravity also causes anything close enough to earth to fall. Gravity holds gasses together like the sun. Gravity also keeps planets in their orbit so that the year length stays the same and so the planets don’t collide. A gravity wave is a wave of gravity emitted by big bodies in orbit. This was confirmed by studying a binary pulsar which is also known as a neutron star that rotates very quickly. Black holes are areas in space that has a so much gravity that not even light can escape a black hole. Most big galaxies have a black hole at their center. Blacks holes existence was predicted by Albert Einstein. (Gravity Online) Issac Newton was a scientist who studied gravity. At only the age of 23 newton wondered how far out gravity could reach. Newton said that gravity pulled objects to earth. Issac Newton assumed that earths gravity worked similar to the suns gravity. The force of the Sun’s gravity gets less powerful as the force gets further away from the sun. Newton’s law about gravity says that the gravity between two things is directly proportional to their masses. If the distance between two objects doubles the force of gravity becomes equal to only one fourth of its original force. (Gravity Online) Gravity originally was misunderstood by Aristotle. Aristotle taught that the heavier the object the faster it falls. Galileo disagreed with this statement and corrected it. Galileo stated “All objects fall with the same acceleration unless air resistance or some other force acts on them.” Issac Newton started studying gravity because he saw an apple fall from a tree. The apple falling from the tree caused a question to spark up in his head wondering how far gravity could reach. In 1687 Issac Newton explained that the further away the force of gravity is from the sun the smaller the amount of force is. Albert Einstein later developed an idea based off Issac Newton’s theories. His idea was that the effects of gravity are the same as the affects of acceleration. Albert Einstein thought that matter and energy can change space time by bending it and that gravity is the force that makes it bend. Space time is three dimensions consisting of length, width and height! (Gravity Online)Buoyancy was originally discovered by Archimedes. Archimedes discovered buoyancy while in a bath tub. He realized when he got in the bath tub the water was displaced due to his new body mass in the water. When he discovered this he ran down the streets without clothes saying eureka! He solved a kings question on wether or not his crown was real gold by putting a real gold crown in water and then putting the kings crown to see if one displaced more water than the other. (How Things Float Online)Buoyancy is very important in the boat world. A boat swings from side to side when the boat is positively buoyant. A submarine’s buoyancy depends on how much air is the tank. When the tank is full it is positively buoyant. The center of gravity is actually where you are standing when you are on a boat. (Ships and Boats Online) My science fair project was floating two types of boats in water and seeing which one floated for the longest. The first boat was a double layered paper boat and the second boat was a duct tape boat. There were three weight intervals and I did three trials per interval with each boat. The intervals were 45 pennies, 65 pennies, and 100 pennies. Buoyancy is involved because it pushed up against the gravity which eventually caused the boats to sink. The duct tape boat proved to have more buoyancy than the double layered paper boat. Gravity is buoyancy biggest opponent when trying to float a boat. Gravity’s force can cause objects to sink.