Daily Science LYF

Note- Air is a bad conductor of heat. 1.   In deserts, days are very hot and night are very cold- This is because of the very low specific hea t of sand which, therefore absorbs the heat rapidly and hence, its temperature rises by a large degree during the day. At nights the sand radiates the heat with equal rate, making the temperature very low. * Specific Heat-  In easy words, it is the amount of heat that a substance required to raise its temperature by 1degree celsius. it is very high for water,  It means water needs more heat to increase its temperature by 1degree celsius. So we use it as a car radiator cooler in our car. 2. Two thin Blanket is war mer than one thick Blanket- This is because the air of enclosed in between the two blankets is a bad conductor of heat. For exactly the same reason, A new quilt is warmer than an old one. This is because the new quilt encloses a large amount of air which is a bad conductor of heat. 3. In winter, birds often s...

What is an Alcoholic Beverage?                                   - Yeast contains Rymase enzymes which convert glucose into ethyl alcohol. So, the beverage contains ethyl alcohol is called an alcoholic beverage. 1. Distilled Beverage- These beverages are prepared by distillation. Amount of alcohol in them may vary from 40-55%. Distilled Beverag e                  % Alcohol                           Sources Brandy                                      (40-50) %                           Grapes Gin                                     ...

We wear cotton clothes in Summer- We should wear cotton clothes in summer. this is because cotton being a good absorber provides more surface area for the evaporation of water. Since The energy required for evaporation is taken up from our body. That's why we feel relief and comfort in such clothes. Water Droplets outside the glass container containing ice-cold water- We saw water droplets on the outer surface of a glass containing ice-cold water. This is because the water vapours present in the air when coming in contact with the glass of ice-cold water, lose their energy and get converted into liquid water which appears in the form of water droplets. After a hot sunny day, People sprinkle water on the roof-  because of the high latent heat of the water helps to cool the hot surface. OR takes more heat from the surface of the roof to get vaporised. We feel cool When some nail polish remover or spirit is kept on our palm- It  is due to the evaporation of remover or ...

The stars seem higher than they actually appear-  as the light from a star enters the earth's atmosphere, it undergoes atmospheric refraction and bends towards the normal at position each time. The upper layers of the atmosphere are rarer than that lower layers. The apparent position of the stars slightly different from its actual position. The star appears slightly higher (above) than its actual position when viewed near the horizon. What is Atmospheric Refraction?                           - Earth can be considered to have consisted of layers of different densities, which acts as a rarer or denser medium with respect to one other. the refraction of light due to these layers is called atmospheric refraction. Advance Sunrise and Delayed Sunset-   The sun is visible to us about two minutes before the actual sunrise, and about two minutes after the actual sunset. this is because of atmospheric refraction....

What is SONAR?                     - The Word SONAR stands for Sound Navigation And Ranging. Sonar is an apparatus used to find the depth of the sea or to locate underwater things like shoals of fish, shipwrecks, and enemy submarines. It is used ultrasonic waves to measure the distance, direction and speed of underwater objects.  Ultrasonic sound waves use because - These waves have high penetrating power, they can penetrate into sea-water to a large extent to locate the underwater objects or to determine the depth of the sea. - These waves cannot be confused with engine noises or other sound made by the ship as they can not be heard by human beings.  - Use of Ultrasonic waves by the Bats                                          - Bats search out prey and fly in dark by emitting and detecting the reflection of ul...

What is Ultrasonic Sound?                                  - The sound of frequency higher than 20,000 Hz, is called Ultrasonic sound.                                 - Ultrasonic waves   can not be heard by human beings. Dogs can hear the ultrasonic sound of frequency up to  50,000Hz . That is why dogs are used for detective work for the police.  - Bats can hear the ultrasonic sonic sound having a frequency up to 120kHz. - Dolphins, bats, porpoises and rats can also produce ultrasonic sound as well as hear the ultrasonic sound. - These are high-frequency waves. They travel in a straight line without bending around the corners. They can penetrate into the matter to a large extent. Due to these properties, ultrasound is used industry and in hospital for medical purposes. 1. Ultrasonography- Ultraso...

What is Sonic Boom?                                   - When the speed of any object exceeds the speed of sound, it is said to have Supersonic Speed . Many objects such as aircraft, bullets, rockets, etc. travel at supersonic speed. When a sound-producing source moves with a speed higher than that of sound, it produces shock waves in air which carry a large amount of energy. The tremendous air pressure variations caused by the shock waves produce a loud burst of sound, known as the Sonic boom.                 It Produces intolerable loud noise which causes pain in our ears. The shock waves produced by a supersonic aircraft have enough energy to shatter glass and even can damage buildings. Everyday Science 1. Ladies voice is sharper than Gents-                               ...

What is Capillarity?                                - A tube with a fine and uniform bore throughout its length is called a capillary tube. When one end of it, is dipped in like water, the liquid rises or falls in the capillary tube above or beloved the surface of the liquid. This phenomenon of rising or fall of liquid in a capillary tube is called capillarity. Application or Use in Daily life- 1. Melted Wax in a Candle-  Melted wax in Candle, rise in capillaries formed in a cotton wick and burn continuously. When we lit a candle then the wax starts melting and also start rising in the cotton wick that contains capillaries inside which help rising wax and candle burn by this continuous process. 2. The coffee powder easily soluble in water-  This is because of water immediately wets the fine granules of coffee by the action of capillarity.  3. The water rises in the Fields or Parks- T...

What is Surface Tension?                                                                               - This is the property of the liquid by which the free surface of the liquid at rest tends to have a minimum surface area.     Surface tension is measured as the force acting per unit length of an imaginary line drawn on the free surface of the liquid.     Surface tension = force/ length = work done/ Change in area NOTE - The surface tension of the liquid decreases with increase in temperature and becomes zero at the critical temperature. Application in Daily life-  1. The Spherical   shape of the liquid- This is because of surface tension, which is the phenomenon of acquiring minimum surface area. Hence leave the water droplets spherical in shap...

What is Pressure?                          - It is the force acting perpendicularly on a unit area of the object.             Pressure = Force/Area= Thrust/Area Note- We know that   the same force can produce different pressures depending on the area over which it acts.  - The same force acting on a smaller area exerts a large pressure while a force on a large area exerts small pressure. Applications in Daily life-   1.  Handles of bags are made broad                          - The handles of bags, suitcase, etc are made broad having more area so that small pressure is exerted on the hand. If we use thin handles, it may hurt our hand as pressure increase with less area. 2. The Tractors have broad tyres      - So that there is less pressure on the ground and the tyres do not sink in...

What is Pressure of liquid?     The normal force exerted by a liquid per unit area of the surface in contact is called Pressure of liquid OR Hydrostatic pressure.  Some special properties of Liquid-  - At any point inside the liquid, the pressure exerted by the liquid is directly proportional to its depth from the surface.  - Liquid exerts pressure on the walls of the vessel containing it and this pressure increases with depth. - At every point in every direction, the pressure exerted inside the liquid is the same. If a number of holes are made at the same height after filling the container with liquid, then the liquid will be released from every hole will be same. What is Pascal's Law?    It states that an increase pressure at one point of the enclosed liquid in equilibrium or rest is transmitted equally to all other points of the liquid and also to the walls of the container, provided the variation in effect of gravity is neg...

Atmospheric Pressure-                                        The Gases surrounding earth is called atmosphere and the pressure exerted by these gases or atmosphere is called Atmospheric Pressure. The pressure difference is the main application of atmospheric pressure. The air goes from high pressure to low pressure. Applications-- 1 . Nose Bleeding at heights At high altitudes, the atmospheric pressure is lesser. Due to the greater difference in blood pressure and atmospheric pressure, the blood vessels exposed inside the nose are more likely to burst and cause bleeding from the nose at heights. 2. Difficult to cook at heights It is difficult to cook at heights as at high altitudes pressure decreases and hence the Boiling point decreases. When we cook the food in the water at high altitudes, water has already evaporated leaving food partially cook or still raw. 3. Drinking St...

What is the Centripetal Force?  A Body performing circular motion is acted upon by a force acted along the radius towards the centre   of the circle. This force is called the Centripetal Force .   Centripetal force = Mass ✖ Centripetal acceleration Difference between the two forces in given diagram What is Centrifugal force? It is regarded  as the reaction of the centripetal force. It acts along the radius and away from the centre of the circle. [ Centripetal works towards the centre and Centrifugal away from the centre] Applications- When a vehicle goes around a curved road, it requires some centripetal force. So, to provide the necessary centripetal force, outer edges of the curved road is raised above the inner edge. This provides a component of the normal reaction of the road and provides the centripetal force. This phenomenon of raising other edges of the road is called Banking of the roads. - Cream separator;         ...

What is the Impulse?                                   - If  a larger force is acting on a body for a very short time, then this force and time are together known as Impulse and large force itself is called impulsive force.    Impulse = change in momentum = Force ✖ Time Note- if we increase the time of impact then the force of impact will be less.  Applications in daily life-                               1. In Catching of the ball   - The players draw their hands back after catching the ball in the direction of the motion of the ball, so they can increase the time of impact which reduces the force of impact and catch the ball easily without hurting themselves. 2. Fragile things wrapped in papers or straw while packing-                  ...

What is Archimedes' Principle?            When a body is fully and partially dipped into fluid, the Force of Buoyancy or Upward Thrust acting on the body will be equal to the weight of the fluid displaced by the body. Note-  Archimedes' principle is valid for both liquid and gases.  Upthrust acting on body = weight of liquid displaced by body  Even Gases like air exerted an upward force on the objects placed in them. It is used in designing ships and submarines, in lactometer [ used to determine the purity of the milk], in Hydrometer[ Used to determine the density of liquid] Application in Daily life- - A Boat floats in water due to upward force called Buoyant Force(or Upthrust) which caused by the pressure of water pushing up on the bottom of the boat. When the boat is gradually lowered into the water, it displaces more and more water. Hence, Buoyant force on it also increases. when this upthrust becomes just enough to support t...

Blood flow and Heart attack-                                                                                                    T he blood flow in the artery and heart attack can be explained using Bernoulli's theorem. With the passage of time, the accumulation of plaque on the inner walls of the artery takes place, making artery constricted, in order to drive this constriction, activity of the heart increases.                                                                               Due to increase activity, the speed of flow of...

Hydro Power Plants-                                     The power plants which converts the potential energy of falling water into electricity, are called Hydro-power plants.  Electricity produced by hydro-power plants is called Hydro electricity. Principle-                   To produce hydroelectricity, high-rise dams are constructed on the river to obstruct the flow of water and thereby collect water in large reservoirs.                                     Due to the rise water level, the Kinetic energy of flowing water gets converted into Potential energy.  The water from a high level is carried through the pipe to the turbine located near the bottom of the dam, which connected to an electric generator.         ...