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TEST YOUR LEARNING, A. Choose the correct answer., 1. b, 2. b, 3. a, 4. d, , 5.c, , B. Fill in the blanks in the, table., 1. Inclined planed wound around, , 2., , a central pole-, , carpenter's screw, bottle cap, Wedge splits or separates two objects, knife,, nail, -, , -, , 3. A wheel with, , a, , lower things, 4., , Wheel and axle, , groove in it, -, , used to, , -, , used to lift, , move, , or, , thingss, , C. Match the words in, column A with those in, , column B., 1. c, , 2. a, , D. Answer the, , 3., , e, , 4. b, , 5. d, , following questions., , 1. A machine is a device that, does work., We use machines for:, , decreasing the amount of force needed, for a work

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changing the distance through which, object is moved, 2., , or, , an, , force is applied, , changing the direction of force, The three classes of levers are, , a), , Class 1 lever: In this lever, the fulcrum is, For, in between the load and the effort., example, see-saw, scissors., , b), c), , load is, Class 2 lever: In this lever, the, effort. For, between the fulcrum and the, nut cracker., wheel, barrow,, example,, effort is, Class 3 lever: In this lever, the, For example,, between the load and fulcrum., , tongs, fishing rod, , 3. Inclined planes, , to, decrease the force needed, the distance, , heavy objects by increasing, is moved., the, object, which, through, move, , 4., , hold, , on, , to the wood, , The threads of a screw, out easily., pulled, be, cannot, firmly and thus, preferred to nails., , Thus, they are

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5. A, , pulley is fixed, , load, the, with, to a support,, , is, , The object, one end of the rope., dtached, the, iTted when the effort on the other end ot, to, , rope is more than the weight of the object., , HOTS, 1. The arm works like, , a, , lever., Effort, , Load, , Fulcrum

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Spiral, , staircases, , av, OCCupy, , ordinary staircases., , less, less area, area, , co, , compared to