Sai Science academy

  Acceleration - acceleration of an object in motion is defined as the rate of change in velocity of the object. (Simpler and understandable definition) a = C h a n g e i n v e l o c i t y / C h a n g e i n t i m e a = C h a n g e i n v e l o c i t y / C h a n g e i n t i m e = > a = v − u / t => a = v − u / t u -> Initial velocity v-> Final velocity t-> Time # If u>v then a = -ve →Retarded motion (Retardation) Acceleration is the rate of change of velocity over a finite and infinitesimal time interval (Complex definition) →It is a vector quantity Average acceleration →It is the ratio of the total change in velocity to the total time taken in which this change in velocity takes place. A avg = Total change in velocity / Total time A avg= Final velocity — Initial velocity / ∆t Created and edited by Sai Group Sai Group If you want to contribute your ideas then please comment down below. In case any doubt frankly ask in comments below, Happy Learning Thank you 🙂

  Distance  is the path covered by the body Distance is a scalar quantity It is dependent on path followed by object Displacement  is the shortest distance covered by the body It is a vector quantity It is independent on the path followed by the object Displacement is defined as the change in position of an object ∆x = X initial — X final ∆x = Xi — Xf # When final position is equal to the initial position we say displacement is zero Distance ≥ Displacement  Created and edited by Sai Group Sai Group  In case of any doubt frankly ask in comments, I will try to answer Viewer's now you can also ask questions and also answer questions, follow Sai Group Happy learning Thank you

Cell  is the basic fundamental and structural unit of life. All living organisms areade up of one or more cells. Microscope  is an instrument used to see objects which are too small to be seen through our Naked eyes.  Cells  are highly organised and all their functions an regulated. It is not just the rate of cell division that is controlled, but also the rate of cell death. If cells are longer needed, they commit suicide by activating an intracellular death program. This process is called programmed cell death or apoptosis. Robert Hooke  in  1665  observed the slices of cork under a microscope, he coined the name as  cell . Anton Van Leeuwenhook  invented  microscope   Mathias Schleiden proposed that all plants are made up of cells. Cell theory was proposed by Schleiden and Schwann. The main postulates of cell theory are: • All living organisms are composed of one or more cells.  • Cell is the basic unit of structure, function...

Electron flow vs. Conventional Current    In 1752, prior to electricity being identified with the electron, Ben Franklin chose a convention regarding the direction of current flow. Franklin assumed that positive charge carriers flowed from positive to negative terminals. We now know this is incorrect. In metals, the charge carrier is the electron whose charge is negative by definition (note negative sign): (−1.6 × 10−19 C)   The flow of electrons is termed electron current. Electrons flow from the negative terminal to the positive. Conventional current or simply current, behaves as if positive charge carriers cause current f low. Conventional current flows from the positive terminal to the negative. Perhaps the clearest waytothinkaboutthis is to pretend as if movement of positive charge carriers constituted current flow.    It is important to realize that the difference between conventional current flow and electron flow in no way effects any real-world behavior...

 Current is the flow of electrons  SI unit - Amperes (A)  Other units - mA - Milli Amperes  1A= 1000mA 1mA = 1/1000A Electric current (I) = V/R  Electric current= Charge / Time  Electrons are negatively charged they flow from the negative terminal to the positive terminal  But  Conventional current or electric current flows from positive to negative  This is the opposite flow get more about here

 Ohm's Law is used to calculate the relationship between voltage, current and resistance in an electric circuit. Ohm's Law - V= I×R V- Voltage (unit of potential difference) I- Electric current R- Resistance  -> V= IR  -> I=V/R  -> R=V/I  ✓ Resistance  Resistance is the restriction to the flow of electrons    SI unit- Ohm Ω  R=V/I  -> Size  More length - More resistance Less length - Less resistance -> Thickness  Thin - More resistance Thick - Less resistance -> Material  Copper - Less resistance Aluminum - More resistance -> Temperature More temperature - More resistance Less temperature - less resistance 

 Big Bang Theory is most accepted theories of creation of universe, but there are some questions left unanswered from this theory. Some questions are there I will try to answer by a new theory(read this with a fresh and accepting mind)  Before starting see the BIG BANG theory  We all know that if anything or any event or any action happening should happen somewhere at some time at some place. You can take any common action it follows this rule  But According to big bang Universe is begun with a bang, then this neglects the rule, we can assume that big bang happened somewhere, but we don't know where it happened this can be asked as a question  Now what created matter and antimatter, or how was it created For now we know there are matter, antimatter and energy  OK if we assume it was created but In time of big bang what the bubble smaller than atom is created of?  If we ask questions like this then there is no end for questions, to understand something...

 1. Resource is anything obtained from environment to satisfy our needs and wants.  2. A natural resource is one obtained from nature  3. Exhaustible natural resources are those which are present in limited quantity in nature . Eg:- Forests, coal, petroleum, natural gas etc 4. Inexhaustible natural resources are those which are present in unlimited quantity in nature . Eg:- Air, water, sunlight etc 5. Petroleum is also known as Black gold

 2. FRICTION 1. Friction is the force which opposes the relative motion between the two Surfaces in contact and it acts on both the surfaces. 2. Friction depends on the nature of surfaces in contact. 3. Friction is independent of the area of contact. 4. Friction is caused by irregularities on the two surface in contact. 5. 6. Static Friction comes into play to counter balance the applied force on the body. When one surface is sliding over the other sliding friction comes into play. 7. When one body rolls over the surface of another body, the resistance to its motion is called the rolling friction. 8. The sliding friction is slightly less than the static friction. 9. The frictional force exerted by fluid is called drag. 10. Friction can be reduced by using:- grease oil, powder, ball bearing and using anti friction alloy. 11. The substance which reduce friction are called lubricants. 12. Rolling friction is smaller than the sliding friction. 13. The sole of the shoes and the tyres of...