N.C.E.R.T. Simplified

                                Ch.10 - Gravitation Q1.  How does the force of gravitation between 2 objects change when the distance between them is reduced to half? A1.  The masses of the 2 objects are M and m        Distance = r/2        Force = GMm/ (r/2)^2                  = GMm/ (r^2/4)                  = 4GMm/ r^2 Q2.  Gravitational force acts on all objects in proportion to their masses. Why then a heavy object does not fall faster than a light object? A2.  The acceleration on the objects does not depend on their masses. The acceleration due to gravity is same on all objects. Thus ideally, a heavy object and light object fall at the same time, but in real life situations, heavy objects fall faster due to the variation in the effect...

Ch. 1 Matter In Our Surroundings Ch. 10 Gravitaion Ch. 15 Improvement In Food Resources

            Ch.1 Matter In Our Surroundings Exercises Q1. Convert the following temperatures to the celsius scale.       (a) 293 K               (b)  470 K A1.   (a)  *(t)K = (t) ° c   + 273            ⇒  293 =  (t) ° c +273           ⇒    (t) ° c = 293 - 273           ⇒    (t) ° c = 20 ° c                (b)   (t)K = (t) ° c   + 273           ⇒  470 =  (t) ° c + 273            ⇒ (t) ° c = 470 - 273            ⇒ (t) ° c  = 197 ° c *(t) refers to temperature. Q2.  Covert the following temperatures to the Kelvin scale.         (a)  25 ° c      ...

Ch-1 Number Systems

              Ch. 1 NUMBER SYSTEMS EXERCISE 1.1 Q1. Is zero a rational number? Can you write it in the form p/q , where p and q are integers and q ≠ 0? A1. Yes 0 is a rational number. It can be written in the form p/q, where p and q are integers and q≠0. For example, 0/5 where p=0 and q=5. Q2. Find six rational numbers between 3 and 4. A2.    ∙ 3= 30/10,         ∙ 4= 40/10 ∴  Six rational numbers between 3 and 4 are 31/10, 32/10, 33/10, 34/10, 35/10, 36/10. Q3.  Find five rational numbers between 3/5 and 4/5 . A3.  ∙ 3/5 = 30/50,         ∙ 4/5 = 40/50 ∴  Five rational numbers between 3/5 and 4/5 are 31/50, 32/50, 33/50, 34/50, 35/50. Q4. State whether the following statements are true or false. Give reasons for your answers.        (i)  Every natural number is a whole number.        (ii) ...