Category Every Day Science

How washing machine works?

Are your favourite jeans dirty? No problem. Put them in the washer. They’ll be clean and ready to wear in no time. When people washed clothes by hand, it took all day. After the clothes were washed, each item had to be twisted to wring out the water.

Today, a washing machine does all the work. First you choose the wash setting. Then you add your clothes and detergent. When you turn the machine on, the machine fills the washing basket, or drum, with water. A tiny computer chip, called a sensor shuts off the waterflow when the level is high enough.

The clothes twist or tumble about in the soapy water. When the clothes are clean, a pump drains the dirty water from the machine. Then the rinse cycle fills the drum with clean water. When the rinse water is pumped out, the timer switches the motor to a faster speed, and the drum spins very quickly. The clothes are flung against the sides of the drum. The water is forced out of the clothes and pumped down the drain. Now your clothes are ready to be tumble dried.

 

Picture Credit : Google

How toaster works?

Toast is tasty for breakfast or a snack. And with a toaster, it’s so easy to make.

First, you put a slice of bread in each toaster slot. A rack holds it in place. Then you push down the lever. The lever is connected to the rack and to a spring. The spring unwinds, but a hook holds the rack down. The heat turns on. The coils inside each slot glow orange.

The heat from the coils toasts the bread. It also heats a metal switch. The switch is made from two types of metal. One type expands from the heat. The other does not. As one half of the metal expands, the switch bends. When it bends, it moves a small bar. This bar pushes against the hook. The rack is released. The spring makes the rack and the toast pop up!

 

Picture Credit : Google

How refrigerator works?

Just a few minutes after you put warm food in a refrigerator, the food feels cooler. The refrigerator carries the heat from the food into the room outside.

How does a refrigerator do this? When a liquid changes to a gas it evaporates. As it evaporates, it takes heat from the things around it. Also, when a gas changes to a liquid, it condenses, and gives off heat. 

Refrigerators are cooled by a special liquid that is easily turned into a gas and then back to a liquid. First, the cool liquid is pumped to tubes inside the refrigerator, where it evaporates. As the liquid changes to a gas, it takes heat from the air inside the refrigerator. This makes the refrigerator cooler.

Then the warm gas is pumped into tubes outside the refrigerator, where it condenses. As the gas changes back to a liquid, it gives off heat. When the liquid cools, it is pumped back into the refrigerator. There it evaporates again. In and out it goes, carrying heat from the refrigerator and keeping the food cold.

Do you ever feel chilled when you get out of the bath or after swimming? This is because the water on your skin is evaporating off your body. It goes into the air where you can’t see it. As this happens, it takes heat away from your body, making you feel chilled.

Water vapour in the air sometimes clings to objects. On a hot day water vapour sticks to a cold glass of water. As more vapour sticks to the glass, it condenses, forming droplets of water on the outside of the glass.

 

Picture Credit : Google

 

How thermometer works?

Are you hot or cold? A thermometer will take your temperature. There are many different kinds used for different purposes. Take your pick.

One type of thermometer has a thin glass tube partly filled with liquid. When the air is warm, the liquid in the tube becomes warm and rises. It rises because heat makes a liquid expand, or take up more space. The warmer it gets, the more space it needs. When the temperature drops, the liquid contracts, or takes up less space, so it moves down the tube. The liquid in many thermometers is a silver-coloured metal called mercury. Some thermometers are filled with coloured alcohol.

A digital thermometer has a metal probe. When the thermometer is turned on, a battery inside sends around an electric current. If the probe is warm, the current will move easily. If the probe is cool, the current will not move as easily. The thermometer shows a temperature reading based on how easily the current moves.

Doctors often use an IR thermometer to detect infrared rays from a person’s eardrum. The hotter you are, the more radiation the thermometer detects. The thermometer converts the amount of radiation to a temperature reading.

 Standard thermometer contains a liquid that moves up when it becomes warm. The liquid drops down when it cools. The lines indicate the temperature.

The lines and numbers on the thermometer indicate degrees. They tell you how much the temperature changed. Degrees are marked with the symbol º. The number 0 ºC is the temperature at which water freezes. This is the same temperature as 32 ºF. The letter C stands for Celsius, and the letter F stands for Fahrenheit.

 

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Who are inventors?

Inventors are men and women who make things that make our life easier.

Many inventions are simple. In 1865 in the U.S.A., S.E. Pettee invented a machine for making paper bags. And Earle Dickson invented the first ready-to-use bandage in 1920.

Some inventions take many years to develop. The great Italian artist Leonardo da Vinci made drawings of his ideas about 500 years ago. He drew an aeroplane, a parachute, and a helicopter. It was more than 300 years before any of these were made.

The American Thomas A. Edison invented the frst light bulb in 1879. But several other men worked on similar designs before Edison did.

To keep their ideas safe and prove they thought of it first, inventors apply for a patent. The patent gives the inventor the right to make his invention or sell his idea. Edison had ore patents than anyone else – he has 1,093!

 

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Which are the inventions we see at home?

Every day we use things that make our lives easier. We flip a switch to turn on the lights. We turn on the tap and fill a glass with water. Our clothes have zippers and snaps that make getting dressed easier. We have alarm clocks to wake us.

What would life be like without lamps or zippers? How would you clean your teeth without a toothbrush or dental floss? Our homes are filled with all sorts of helpful inventions.

The refrigerator allows the modern household to keep food fresh for longer than before. Freezers allow people to freeze food and extend its expiry date for even longer periods.

A washing machine is a machine that uses water to wash laundry, such as clothing and sheets. Bendix Corporation introduced the first domestic automatic washing machine in 1937. Imagine this; this very common household appliance was not available prior to that date!

A television set, more commonly called TV, is a device used for the purpose of viewing television broadcast. It was introduced in 1920 in mechanical form.

However, the modern color television was not introduced until 1940.

The Television has become commonplace in our homes, offices, and institutions, particularly as a prime source for advertising, entertainment, and news.

 

Picture Credit : Google