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Science, , Py, , >, , Amrutha Varshini Vidyalaya, 6th Std, , 10 Motion and Measurement of Distances, , Give two examples each of modes of transport used on land,, water and air., , : On land — Buses and Trains, , On water — Ships and Boats, On air — Helicopters and Aeroplanes., , Why can a pace or a footstep not be used as a standard unit of, length?, , : The length of a pace or a footstep varies from person to person., , Hence it cannot be used as a standard unit of length., , Arrange the following lengths in their increasing magnitude., 1 metre, 1 centimetre, 1 kilometre, 1 millimetre, 1 millimetre < 1 centimetre < ] metre < 1 kilometre., , The height of a person is 1.65m, Express it into cm and mm, , 1.65 x 100 cm = 165 cm,, 165 cmx 10 = 1650 mm, , The distance between Radha’s home and her school is 3250m., Express this distance in km., , : 1000 m=1km Imetre =100cm, , 3250 m = 3250/1000 = 3.25 km. 100cm = 1000millimetre, , While measuring the length of a knitting needle the reading of, the scale at one end is 3.0 cm and at the other end is 33.1 cm., , What is the length of the needle?, , : The actual count of the length of the needle :, , 33.1- 3.0 cm= 30.1 cm, Write the similarities and differences between the motion ofa, , bicycle and a ceiling fan that has been switched on., , : SIMILARITIE :, , Both the ceiling fan and the wheels of a bicycle show circular, motion.
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10., , 11., , 12., , DIFFERENCE, A bicycle shows rectilinear motion while a ceiling fan does not., , Why could you not use an elastic measuring tape to measure, distance? What would be some of the problems you would, meet in telling some one about a distance you measured with, , an elastic tape?, , : Anelastic tape is flexible and can be stretched. Thus, each time it, , will give different readings for the same length measured, There, fore, it is impossible to measure accurate distance from an elastic, , measuring tape., Give two examples of periodic motion and two examples of, periodic motion, , : 1. Motion of a pendulum clock, , 2. Motion of a swing, , Define rest and motion., , : The objects which do not change their positions with time are said, , to be at rest. The objects which change their positions with time, are said to be in motion., , State two precautions to be observed while measuring length, with the help of a metre scale., , : Two precautions are :, , 1. The initial point of distance must coinside with the zero, , reading of metre scale., 2. The eye should be kept in line with the point of measurement., , Why do we need standard unit for measurement?, , : We need standard unit for measurement to make our judgement, , more reliable and accurate. There should be uniformity in, measurement. For the sake of uniformity we need standard units, SI units are used in science and technology almost, , universally.
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13., A?, , Give two example for each of the following, 1. Linear motion: * Rolling of ball on ground, * Moving of bicycle on road, , 2. Spinning motion :* Rotating fan, * Wheel of sewing machine, , 3. Oscillatory motion: * Pendulum of clock, * Motion of a child on a swing, , 4. Periodic motion : * Pendulum of clock, * Motion of heart beat, , 5, Vibrational motion: * String of a guitar, * Surface of drums, , 6. Circular motion : * Rotation ofa fan, * Bicycle of wheel, , 7. Random motion : * Motion of foot ball player, * Movement of mosquito
