{"id":2990,"date":"2023-10-04T08:57:39","date_gmt":"2023-10-04T08:57:39","guid":{"rendered":"http:\/\/localhost\/ecole9ja\/?p=2990"},"modified":"2023-10-04T09:04:49","modified_gmt":"2023-10-04T09:04:49","slug":"week-2-ss2-first-term-physics-notes","status":"publish","type":"post","link":"https:\/\/ecolebooks.com\/nigeria\/posts\/week-2-ss2-first-term-physics-notes\/","title":{"rendered":"Week 2 – SS2 First Term Physics Notes"},"content":{"rendered":"

\u00a0WEEK 2
\n<\/strong>SCALAR AND VECTOR QUANTITIES
\n<\/strong><\/p>\n

CONTENTS
\n<\/h2>\n
    \n
  • \n
    Concept of scalar and vector quantities\n<\/div>\n<\/li>\n
  • \n
    Vector representation, addition of vectors\n<\/div>\n<\/li>\n
  • \n
    Resolution of vectors and resultant\n<\/div>\n<\/li>\n<\/ul>\n

    \u00a0CONCEPT OF SCALAR AND VECTOR QUANTITIES
    \n<\/strong>Physical quantities are divided into scalar and vector quantities.
    \nA scalar is one which has only magnitude (size) e.g. distance, speed, temperature, volume, work, energy, power, mass etc.
    \nA vector quantity has both magnitude and direction e.g. force, weight, magnetic flux, electric fields, gravitational fields etc.<\/p>\n

    VECTOR REPRESENTATION
    \n<\/h2>\n

    A vector quantity can be graphically represented by a line drawn so that the length of the line denotes the magnitude of the quantity. The direction of the vector is shown by the arrow head.
    \nADDITION AND SUBTRACTION OF VECTORS
    \n<\/strong>\"\"\/Two or more vectors acting on a body in a specified direction can be combined to produce a single vector having the same effect. The single vector is called the resultant.
    \nFor example:
    \n(a)\u00a0 Two forces Y and X with magnitude of 3N and 4N respectively acting along the same direction will produce a resultant of 7N (algebraic sum of the two vectors).
    \n(b) If Y and X act in opposite direction, the resultant will be 1N.
    \n(c) If the two vectors are inclined at 900<\/sup> to each other, Pythagoras theorem is used.
    \n\"\"\/Y
    \n\"\"\/\"\"\/\"\"\/3N <\/p>\n

    \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0
    \n\u00a0\"\"\/\"\"\/\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 ) \u03b8
    \n4N X
    \n\u00a0
    \n\u00a0R2<\/sup> = X2<\/sup> + Y2<\/sup>
    \n\t\tR2 <\/sup>= 42<\/sup> + 32<\/sup>
    \n\t\tR2<\/sup> =16 + 9
    \nR2<\/sup> = 25
    \nR = \u221a 25 \u00a0\u00a0\u00a0\u00a0
    \nR = 5N
    \nTan \u03b8 = Y\/X
    \n\u03b8 = tan-1<\/sup>(Y \/X)
    \n\u03b8 = tan-1<\/sup>(3\/4)
    \n\u03b8 = tan-1<\/sup>(0.75)
    \n\u03b8 = 36.90<\/sup>
    \n\t\t (d) If the two vectors are inclined at an angle less than 900 <\/sup>or more than 900<\/sup>, the resultant is obtained by using Parallelogram law of vector addition.
    \nParallelogram law of vector addition states that if two vectors are represented in magnitude and direction by adjacent sides of a parallelogram , the resultant is represented in magnitude and direction by the diagonal of the parallelogram drawn from the common point
    \n<\/em><\/p>\n

    RESOLUTION OF VECTORS
    \n<\/h2>\n

    A single vector can be resolved into two vectors called components. A vector F represented as the diagonal of the parallelogram can be resolved into its component later taken as the adjacent sides of the parallelogram. \u00a0
    \n\"\"\/\u00a0
    \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0F
    \nY
    \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0) \u03b8\u00a0\u00a0\u00a0\u00a0X\u00a0
    \nSin\u03b8 = y \/F
    \ny = f sin \u03b8 (vertical component)
    \nCos\u03b8 = x \/F
    \nx = F cos \u03b8 (horizontal component)
    \nThe direction of F is given by
    \nTan \u03b8 = y\/x
    \n\u03b8 = tan-1 (y\/x) <\/p>\n

    THE RESULATNT OF MORE THAN TWO VECTORS
    \n<\/h2>\n

    To find the resultant of more than two vectors, we resolve each vector in two perpendicular direction s add all the horizontal components X, and all the vertical components, Y.
    \nFor example, consider four forces acting on a body as shown below<\/p>\n

    \u00a0\"\"\/Figure 1:
    \n F2 F1 \u00a0\u00a0\u00a0\u00a0
    \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 \u03982<\/sub>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 \u03b81<\/sub>
    \n\t\t \u00a0\u00a0\u00a0\u00a0\u03983<\/sub> \u03b84<\/sub>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0
    \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0F3\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0F4<\/p>\n

    \u00a0Figure 2:
    \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0Y\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0R<\/p>\n

    \u00a0
    \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0) \u221e
    \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0X
    \nAdd all the resolved horizontal components
    \nFigure 1:
    \nX = F1 cos \u03b81 + (-F2 cos \u03b82 ) + (-F3 cos \u03b83 ) + F4 cos \u03b84
    \nY= F1 sin \u03b81 + F2 sin\u03b82 + (-F3 sin\u03b83) + (-F4 sin\u03b84)
    \nFigure 2:
    \nR2<\/sup> = X2<\/sup> + Y2 <\/sup>
    \n\t\tR = \u221aX2<\/sup>+ Y2<\/sup>
    \n\t\tAnd the direction \u221e is given by
    \n Tan \u221e = y\/x <\/p>\n

    \u00a0CLASSWORK
    \n<\/strong><\/p>\n

      \n
    1. \n
      Define vector\n<\/div>\n<\/li>\n
    2. \n
      What is the difference between scalar and vector\n<\/div>\n<\/li>\n
    3. \n
      Find the vertical and horizontal components of 500N force when it is inclined at (i) 600<\/sup> (ii) 900<\/sup> (iii) 1500<\/sup> to the ground level\n<\/div>\n<\/li>\n<\/ol>\n

      ASSIGNMENT
      \n<\/strong>SECTION A<\/strong><\/p>\n

        \n
      1. \n
        Two forces, whose resultant is 100N, are perpendicular to each other. If one of them makes an angle of 600<\/sup> with the resultant, calculate its magnitude: (a) 200.0N (b) 173.2N (c) 86.6 (d) 115.5\n<\/div>\n<\/li>\n
      2. \n
        A boy pulling a load of 150N with a string inclined at an angle of 300<\/sup> to the horizontal. If the tension in the string is 105N, the force tending to lift the load off the ground is: (a) 52.5N (b) 202.5N (c) 75N (d) 255N\n<\/div>\n<\/li>\n
      3. \n
        A lorry travels 10km northwards, 4km eastwards, 6km southwards and 4km westwards to arrive at a point T. What is the total displacement? (a) 6km east (b) 4km north (c) 6km north (d) 4km east\n<\/div>\n<\/li>\n
      4. \n
        The resultant of two forces acting on an object is maximum when the angle between them is (a) 1800<\/sup> (b) 900<\/sup> (c) 450<\/sup> (d) 00<\/sup>\n\t\t\t\t<\/div>\n<\/li>\n
      5. \n
        A boy pulls his toy on a smooth horizontal surface with a rope inclined at 60 to the horizontal .If the effective force pulling the toy along the tension in rope (a) 2.5 N (b) 4.33N (c) 5.0 N (d) 8.66N (e) 10.0N\n<\/div>\n<\/li>\n<\/ol>\n

        SECTION B
        \n<\/strong><\/p>\n

          \n
        1. \n
          A body of weight W newton rests on a smooth plane inclined at an angle \u04e9 to the horizontal. What is the resolved part of the weight in newton along the plane?\n<\/div>\n<\/li>\n
        2. \n
          A lawn-mower is pushed with a force 50N. If the angle between the handle of the mower and the ground is 300<\/sup>, (a) calculate the magnitude of the force that is pressing the lawn-mover directly into the ground (b) calculate the effective force that moves the mower forward (c) why does the lawn mower move forward and not downward into the ground?\n<\/div>\n<\/li>\n<\/ol>\n

          \u00a0
          \n\u00a0
          \n\u00a0<\/p>\n

            \n
          1. \n
            \"\"\/Calculate the resultant force in the diagram \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a012N\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a010N\n<\/div>\n

            400<\/sup>\u00a0\u00a0\u00a0\u00a0 300<\/sup>\n\t\t\t\t<\/li>\n<\/ol>\n

            \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 600
            \n<\/sup>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a09N\u00a0\u00a0\u00a0\u00a015N<\/p>\n

            \u00a0
            \n\u00a0
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            \n\u00a0
            \n\u00a0
            \n\u00a0
            \n\u00a0
            \n\u00a0
            \n\u00a0
            \n\u00a0
            \n\u00a0
            \n\u00a0
            \n\u00a0
            \n\u00a0
            \n\u00a0
            \n\u00a0
            \n\u00a0
            \n\u00a0
            \n\u00a0
            \n\u00a0
            \n\u00a0
            \n\t\t\t<\/strong>\u00a0<\/p>\n","protected":false},"excerpt":{"rendered":"

            \u00a0WEEK 2 SCALAR AND VECTOR QUANTITIES CONTENTS Concept of scalar and vector quantities Vector representation,…<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1,242],"tags":[],"class_list":["post-2990","post","type-post","status-publish","format-standard","hentry","category-posts","category-first-term-ss2-physics"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/ecolebooks.com\/nigeria\/wp-json\/wp\/v2\/posts\/2990","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/ecolebooks.com\/nigeria\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/ecolebooks.com\/nigeria\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/ecolebooks.com\/nigeria\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/ecolebooks.com\/nigeria\/wp-json\/wp\/v2\/comments?post=2990"}],"version-history":[{"count":1,"href":"https:\/\/ecolebooks.com\/nigeria\/wp-json\/wp\/v2\/posts\/2990\/revisions"}],"predecessor-version":[{"id":2991,"href":"https:\/\/ecolebooks.com\/nigeria\/wp-json\/wp\/v2\/posts\/2990\/revisions\/2991"}],"wp:attachment":[{"href":"https:\/\/ecolebooks.com\/nigeria\/wp-json\/wp\/v2\/media?parent=2990"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/ecolebooks.com\/nigeria\/wp-json\/wp\/v2\/categories?post=2990"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/ecolebooks.com\/nigeria\/wp-json\/wp\/v2\/tags?post=2990"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}