1. E_ _ _ _ _ _ _ _ is the act of forcing or pushing something out of something.2. To s_ _ _ _ means to cut through something and make it break.3. When the machine is old, the engineer usually uses cream or other substances to p_ _ _ _ _ it.4. To w_ _ _ means to join pieces of metal together by heating their edges and pressing them together5. In Hyundai Company, workers use a pincher machine to p_ _ _ _ a row of holes in the metal sheet.6. The property of t _ _ _ _ _ _ _ _ _ _ _ of plastics helps to look through the materials easily. It depends on the type and structure of the polymer.7. With the addition of p _ _ _ _ _ _ _ _ _ _ _ , plastics becomes softer and more flexible and they can be used in electrical cable insulation, clothing.8. Plastics have the property of s _ _ _ _ _ _ _ _ , therefore they are very hard and strong and can be used widely.9. Low-Density P _ _ _ _ _ _ _ _ _ _ _ is sometimes recycled. It is a very healthy plastic that tends to be both durable and flexible.10. Thermoset plastics are stronger than thermoplastics but can not be recycled and have to be d _ _ _ _ _ _ _

1. L_ _ _ is a very heavy, soft, dark grey poisonous metal, usually in the center of pencils. 2. The machines should be made of ­­­d_ _ _ _ _ _ materials so that they can be used for a long time. 3. Iron is a r_ _ _ _ metal that is used to make steel so it's hard to bend. 4. Copper is used for wire because it is more d_ _ _ _ _ _ than most other metals. 5. The pipe needs to bend several times as we pass it into the structure, so we don’t want it to be stiff. We should choose a f_ _ _ _ _ _ _ pipe. 6. Glass which is a b_ _ _ _ _ _ material used in the production of our mobile phones may break if the phone is dropped. 7. High temperature super alloys are used in applications requiring material that can w_ _ _ _ _ _ _ _ extreme forces and severe oxidizing. 8. T_ _ _ _ _ _ _ is a chemical element that is a light, strong, white metal. Its symbol is Ti. 9. Copper can be mixed with tin and led to produce b_ _ _ _ _. 10. T_ _ _ _ _ _ _ _ _ _ _ _ _ can be melted and formed into shapes that become hard, and can then be melted again.

1. Give two examples each of situations in which you push or pull to changethe state of motion of objects.2. Give two examples of situations in which applied force causes a change inthe shape of an object.3. Fill in the blanks in the following statements:(a) To draw water from a well we have to ——— at the rope.(b) A charged body ———— an uncharged body towards it.(c) To move a loaded trolley we have to ———— it.(d) The north pole of a magnet ———— the north pole of another magnet.© NCERTnot to be republishedSCIENCE1444. An archer stretches her bow while taking aim at the target. She thenreleases the arrow, which begins to move towards the target. Based onthis information fill up the gaps in the following statements using thefollowing terms:muscular, contact, non-contact, gravity, friction, shape, attraction(a) To stretch the bow, the archer applies a force that causes a changein its ——.(b) The force applied by the archer to stretch the bow is an example of ——— force.(c) The type of force responsible for a change in the state of motion of thearrow is an example of a ———— force.(d) While the arrow moves towards its target, the forces acting on it aredue to ———— and that due to ———— of air.5. In the following situations identify the agent exerting the force and theobject on which it acts. State the effect of the force in each case.(a) Squeezing a piece of lemon between the fingers to extract its juice.(b) Taking out paste from a toothpaste tube.(c) A load suspended from a spring while its other end is on a hook fixedto a wall.(d) An athlete making a high jump to clear the bar at a certain height.6. A blacksmith hammers a hot piece of iron while making a tool. How doesthe force due to hammering affect the piece of iron?7. An inflated balloon was pressed against a wall after it has been rubbedwith a piece of synthetic cloth. It was found that the balloon sticks to thewall. What force might be responsible for the attraction between the balloonand the wall?8. Name the forces acting on a plastic bucket containing water held aboveground level in your hand. Discuss why the forces acting on the bucket donot bring a change in its state of motion.9. A rocket has been fired upwards to launch a satellite in its orbit. Namethe two forces acting on the rocket immediately after leaving the launchingpad.10. When we press the bulb of a dropper with its nozzle kept in water, air inthe dropper is seen to escape in the form of bubbles. Once we release thepressure on the bulb, water gets filled in the dropper. The rise of water inthe dropper is due to(a) pressure of water(b) gravity of the earth(c) shape of rubber bulb(d) atmospheric pressureE X E R C I S E S© NCERTnot to be republished

Read the text and fill in the blanks WITH ONLY ONE WORD.Machining and CNCMaching is the use of machines to cut pieces of material (called workpiece) and shape them into components. The tools used in machining, to make holes, grooves, threads, etc., are called machine tools. Metal is often machined. As it is cut, waste is produced, called swaft or chips. During machining, a liquid called cutting fluid may be pumped onto the workpiece to act as a coolant, keeping the workpiece cool. In manufacturing, machining is usually guided by computers called computer numerical control (CNC) systems. Often, design information ( on shapes and sizes of components) is fed directly into CNC systems from computer aided design/ computer aided manufacturing (CAD/CAM) software.Machining with cutting toolsMilling is cutting done by a milling machine, often using toothed cutting discs ( wheel with teeth that have sharp edges). When a workpiece is milled, it is held in a fix position on the machine, and is shaped by cutting tools which rotate (spin) while being moved over the surface of the workpiece.Turning is a technique for cutting components that have a circular cross-section. The workpiece is turned by a machine called a lathe, which rotates the workpiece. A fixed machine tool is then moved against the rotating worpiece to cut material from it.Punching: Thin materials can be cut by applying pressure in order to shear them- that is, cut them with scissoring force ( in engineering, called a shear force). Small shapes, such as circles, can be sheared from sheets using a machine called a punch which pushes a die ( a shaped tool) through the sheet.1. The waste metal produces during machining is called 2. Metal gets hot during cutting, so cutting fluid can be used as a .3. Drawings can be produced and traferred to the machining process using .4. A milling machine uses toothed cutting discs to mill a held in a fix position on the machine.5. Turning means cutting components that have a circular cross-section. A lathe is used to turn and the workpiece.

Read the text and fill in the blanks WITH ONLY ONE WORD.Machining and CNCMaching is the use of machines to cut pieces of material (called workpiece) and shape them into components. The tools used in machining, to make holes, grooves, threads, etc., are called machine tools. Metal is often machined. As it is cut, waste is produced, called swaft or chips. During machining, a liquid called cutting fluid may be pumped onto the workpiece to act as a coolant, keeping the workpiece cool. In manufacturing, machining is usually guided by computers called computer numerical control (CNC) systems. Often, design information ( on shapes and sizes of components) is fed directly into CNC systems from computer aided design/ computer aided manufacturing (CAD/CAM) software.Machining with cutting toolsMilling is cutting done by a milling machine, often using toothed cutting discs ( wheel with teeth that have sharp edges). When a workpiece is milled, it is held in a fix position on the machine, and is shaped by cutting tools which rotate (spin) while being moved over the surface of the workpiece.Turning is a technique for cutting components that have a circular cross-section. The workpiece is turned by a machine called a lathe, which rotates the workpiece. A fixed machine tool is then moved against the rotating worpiece to cut material from it.Punching: Thin materials can be cut by applying pressure in order to shear them- that is, cut them with scissoring force ( in engineering, called a shear force). Small shapes, such as circles, can be sheared from sheets using a machine called a punch which pushes a die ( a shaped tool) through the sheet.

Students will know more about machine tools such as lathes and mills when joining the I_ _ _ _ _ _ _ _ _ M_ _ _ _ _ _ _ class.  Trang trước