ï»¿Density and Its Applications
Formula of Density-
-Solids are usually hard and strong compared to liquids and gasses.
-This makes solids suitable for constructing buildings, bridges and vehicles.
-Iron is used to make bridges while wood is used to build houses and furnitures.
-Rubber and plastic are flexible. They are used to make hoses and wire coverings.
-Polyvinylchloride (PVC) is a type of plastic that can be used to make some pipes.
-The fluidity of liquid and the fact that they can take the shape of their containers are useful when manufacturing items such such as plastic goods.
-Solid plastic which is melted into liquid, is poured into specifically-shaped containers or moulds.
-As the liquid cools, it turns into solid following the shape of the moulds. This allows us to manufacture many useful items.
Sinking and Floating of Submarines
-A submarine will sink into the deep sea when its ballast tanks are filled with sea water.
-The submarine will rise to the surface of the sea when its ballast tanks is removed.
Killing Mosquito Larvae
-An insecticide is sprayed on surface of stagnant water.
-Mosquito larvae in the water will die because the insecticide which floats on the water will cut off their air supply.
Meteorological and Hot-Air Balloons
-Helium is less dense than the air and floats in the atmosphere. It is used to fill meteorological balloons.
-The air in a hot-air balloon expands when it is heated, causing it to be less dense than the air outside.
-To lower the hot-air balloon, the heater is switched off to allow the air in the balloon to cool. This is because the cool air in the balloon is denser than the air outside.
-A raft is made up of bamboo poles which are tied together.
-The raft can float because the bamboo poles are less dense than water.
-Logs, which have a lower density than water, can be transpoted by the river to the factory that is situated on the river bank.
Buoy and Float
-A buoy which floats on the sea is used to indicate dangerous or safe areas for boats.
-A float can be used to prevent someone who is learning to swim from drowning.
Boat and Ship
-Boats and ships are able to float because they have hollow spaces which are filled with air.
-The density of a boat or ship is lower than that of water.
-Fishermen use plastic balls as floats that are attached to the fishing net.
-The floats make the fishing net stay upright in the sea for catching fish and the floats can be seen easily by fishermen.
-Metal balls are used to sink the net so it opens widely to catch fish.
-Floating bags are used to control an oil spill in the sea by surrounding it to minimize its spreading in the sea.
Mining of Ores
-Tin ore sinks to the bottom of palong railings because tin ore is denser than water.