Measurements

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1.general physics  1.1 length and time  -i-Physical Quantity Physical Quantities A physical quantity is a property of an object that can be measured with a measuring instrument. A physical quantity is usually expressed as “a magnitude ( numerical value)  and a  physical unit or more ” Example :- Normal body temperature of a healthy human being is  37  0 C -ii-Length Measuring Length. Length is “the distance between two points in a space”. According to SI units, the length quantity is expressed in meter. There are several kinds of measuring devices used to measure quantity of length, among others, are as follows. Tools used… a-   Measuring tape. b-   Ruler c-   Vernier callipers. d-    Micrometer Measurement of length Length is measured accurately through many methods. Here are some: Method Notes Ruler Used to make simple measurements accurate to  0.1 cm  (1 mm) Vernier caliper Used to make simple measurements accurate to
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Effects of forces

Effects of forces

  • A force may produce a change in size and shape of a body









    bending, twisting, compression, extension are the main ways for a body to change size, shape and motion

    if two forces are acting on the same line they are either acting together or against each other. the resultant force of two forces acting together is the sum of the forces in the direction that they were pulling/pushing. if they are acting against each other the resultant force is the bigger force minus the smaller force in the direction of the bigger force. if the forces are the same size they cancel each other out.



    to calculate the force, mass or acceleration of an object you can rearrange the equation force = mass X acceleration (provided you have the other two variables).
    if you threw a tennis ball, how hard the throw was depends on it’s mass and how fast the throw was.













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