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Showing posts from November, 2015

Heat Problems

Specific Heat Problems 1.    5.0 g of copper was heated from 20°C to 80°C. How much energy was used to heat Cu? (Specific heat capacity of Cu is 0.092 cal/g °C) 2.    How much heat is absorbed by 20g granite boulder as energy from the sun causes its temperature to change from 10°C to 29°C? (Specific heat capacity of granite is 0.1 cal/gºC) 3.    How much heat is released when 30 g of water at 96°C cools to 25°C? The specific heat of water is 1 cal/g°C. 4.    If a 3.1g ring is heated using 10.0 calories, its temperature rises 17.9°C. Calculate the specific heat capacity of the ring.   5.    The temperature of a sample of water increases from 20°C to 46.6°C as it absorbs 5650 calories of heat. What is the mass of the sample? (Specific heat of water is 1.0 cal/g °C) 6.    The temperature of a sample of iron with a mass of 10.0 g changed from 50.4°C to 25.0°C with the release of 47 calories of heat...

Complex Vector addition

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What if the angle of inclination between the vectors in 90 degrees. You are aware of your favorite  This will help you. Let's take an Example. Bholu starts walking towards north and walks 11 km stops takes a right turn and starts walking towards East and walks for another 11 km The result (or resultant) of walking 11 km north and 11 km east is a vector directed northeast as shown in the diagram to the right. Since the northward displacement and the eastward displacement are at right angles to each other, the Pythagorean theorem can be used to determine the resultant (i.e., the hypotenuse of the right triangle).   ART : 1. Vector rule says you can displace the vector so while doing so we choose the 2nd vector (Eastward) . You can choose 1st as well. 2. Make sure that you Join tail of one vector with head of another ( Like a nut bolt pair forms a couple ) 3. After doing so we see a right angled triangle formation its Hypotanus will give us the resultant vecto...

Easy Vector Addition

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Easy vector addition that you have already performed before in case of Newton's laws of Motion Two vectors can be added together to determine the result (or resultant). In our discussion of Newton's laws of motion, that the net force experienced by an object was determined by finding the vector sum(Net force) of all the individual forces acting upon that object. During that what we did is called simple vector addition Given Below are some examples :- Reminding these things, take examples of all those cases of Pulley, Wedge and other NLM problems where we have used the simple vector addition.  But what when two forces are inclined to each other there comes the use Complex Vector Addition. To be Continued... 

Directions of Vector

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While we Study vector we have certain privileges (Humara Haq) We call it " Aazadi Ka Neeyam " We can never change the direction unless we are told in the question to do so. We can displace the vector in any direction keeping its angle fixed (i.e again direction) Above two will be more clear with some illustrations. Vectors can be directed due East, due West, due South, and due North. But some vectors are directed northeast (at a 45 degree angle); and some vectors are even directed northeast, yet more north than east. Thus, there is a clear need for some form of a convention for identifying the direction of a vector that is not due East, due West, due South, or due North. There are a variety of conventions for describing the direction of any vector. The two conventions that will be discussed and used in this unit are described below: The direction of a vector is often expressed as an angle of rotation of the vector about its "tail" from east, west...

Vector

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Vector quantities are often represented by scaled vector diagrams. Vector diagrams depict a vector by use of an arrow drawn to scale in a specific direction. Vector diagrams were introduced and used in earlier units to depict the forces acting upon an object. Such diagrams are commonly called as free-body diagrams . An example of a scaled vector diagram is shown in the diagram at the right. The vector diagram depicts a displacement vector. Observe that there are several characteristics of this diagram that make it an appropriately drawn vector diagram. **Scale : as we do keep scale while drawing a graph. a scale is clearly listed Head of the vector always points towards the Direction. Magnitude of the vector is shown by the length of the vector. In this case, the diagram shows the magnitude is 20 m and the direction is (30 degrees West of North). ** Length : Sometimes it is not possible to show higher magnitudes like 100 km in that case we use scale. ...

Logarithm Log Rules

The basic idea A logarithm is the opposite of a power. In other words, if we take a logarithm of a number, we undo an exponentiation . Let's start with simple example. If we take the base b = 2 and raise it to the power of k = 3 , we have the expression 2 3 . The result is some number, we'll call it c , defined by 2 3 = c . We can use the rules of exponentiation to calculate that the result is c = 2 3 = 8. Let's say I didn't tell you what the exponent k was. Instead, I told that the base was b = 2 and the final result of the exponentiation was c = 8 . To calculate the exponent k , you need to solve 2 k = 8. From the above calculation, we already know that k = 3 . But, what if I changed my mind, and told you that the result of the exponentiation was c = 4 , so you need to solve 2 k = 4 ? Or, I could have said the result was c = 16 (solve 2 k = 16 ) or c = 1 (solve 2 k = 1 ). A logarithm is a function that does all this work for you. We defi...