Sujit Prasad Kushwaha

                                                                  New Syllabus Course Title: Scientific Communication                                                                   Full Marks:50 Course No: SC 101                                                   ...

 1. Read the following passage and answer the questions given below briefly: [10] There is a considerable scientific disagreement about the medical hazards of the new pollutants; about the effects of DDT now found in human bodies, about the diseases due to smog, or about the long range effects of fallout. But the crucial point is that the disagreements exists, for they reveal that we have risked these hazards before we know what harm they might do. Unwittingly we have loaded the air with substances that interfere with the functioning of the blood. Because we wanted to build nuclear bombs and kill mosquitoes; we have burdened our bodies with strontium-90 and DDT, with consequences that no one can now predict. We are, in effect, conducting a high experiment ourselves. A generation hence-too late to help-public health statistics may reveal what hazards are associated with these pollutants. ('Science and Survival,' Barry commoner) a) What are the three pollutants with which man has...

Conservation of Linear Momentum The total quantity of motion contained in a body is called linear momentum . It is denoted by $\vec{P}$ and defined as the product of mass and velocity of the body. For a body of mass $m$ and velocity $v$, its linear momentum $\vec{P}$ in vector form is given by: $$\vec{P} = m\vec{v}$$ In terms of magnitude only, $$P = mv$$ SI unit of linear momentum is $\text{kg m s}^{-1}$ or Ns, and dimensional formula is $[MLT^{-1}]$. Law of Conservation of Linear Momentum It states that, "the total linear momentum of a system of particles remains constant, provided that no external force acts on the system" . Proof: From Newton's second law of motion , $$F = \frac{dP}{dt}$$ In absence of force, $$\frac{dP}{dt} = 0 \;\Rightarrow\; P = \text{constant}$$ Proof (for a system of particles): Let us consider a system of $n$ particles of total mass $M$. Then, $$M = m_1 + m_2 + \cdots + m_n$$ So, $$P = P_1 + P_2 + \cdots + P_n$$ Differe...

This is the mathematics formulae book for class 12 students. Here, we have covered all the formulae needed to solve the questions of Mathematics. Permutation The total arrangement of total objects taken some or all at a time is called permutation. The permutation of 'n' objects taken 'r' at a time is denoted by $^np_{r}$ and is defined by; 1. $^np_{r}=\frac{n!}{(n-r)!}$ 2. Permutation of an object, all different;$$=\frac{n!}{p!\,q!\,r!}$$ where,  n=total objects p=repetition of first kind  q=repetition of second kind r=repetition of third kind 3. Circular permutation= $(n-1)!$ 4. If clockwise and anticlockwise arrangement are not distinguishable [necklace of beads and beads into bracelet]; Total number of permutation=$\frac{(n-1)!}{2}$ Combination The selection of total objects taken some or all at a time is called combination. The combination of 'n objects taken 'r' at a time is denoted by $^nc_{r} \, or \, c(n,r)$ and defined by; $$^nc_{r}=\frac{n!}{(n-r)!...

 Attempt all the questions. 1. Read the following passage and answer the questions given below. [10] Pollution-the simple visible kind of pollution is now worldwide. When Apollo 8 took photographs of the earth's surface, where did they reveal the most serious smog and polluted air? Not Los Angeles, which as somehow got the reputation of having biggest and nastiest smog, but over Osaka and Tokyo in Japan. Along this strips, 34 tons of dirt a month fall on every square kilometer, compared to a mere 17 tons in New York. Coastal vessels collide regularly or run aground because they cannot see each other's navigation lights in day-light, or because light buoys are invisible. Traffic policeman go back to the police-station after four hours of duty and breathe pure oxygen from the oxygen cylinders to re-oxygenate their carbon monoxide loaded blood. In cafes and shopping centers coin-in-the slot machines give oxygen to shoppers who feel themselves about to collapse. In school, children...