First exercise p.90 to 93 1-Choose: 1- c 2-b 3-b 4-c 5-a 6-c 7-b 8-c 9-c 10-b 11-a 12-a 2- x=2 y=10 3-Give reasons for: 1- Because they may increase the distance, move force from one place to another, increase the speed, avoid dangers, be accurate in performance. 2- Because the force arm is longer than the resistance arm as resistance lies between fulcrum and force. 3- Because the increase force, increase distance, move force from one place to another, increase the speed, avoid dangers, be accurate in performance. 4- Because it has high melting point and it emits light when it is heated as electric current passes through. 5- When one lamp is damaged the other lamps will not turned off and the intensity of the lamps will not be affected by the increase of their number. 6- To connect the filament with the electric current and to keep positions of the lamp in upright position. 7- To help the root penetration through soil particles and to facilitate water absorption. 8- Because it contains a large vacuole that contains concentrated salt solution to help water transmission from the soil to the root hair by osmosis. 9- To enables the plant to lose water in the form of water vapor through stomata. 10- Because the epidermal cells are lost from time to time during root growth through the soil particles. 11- Their shapes change to open or close the stoma. 12- It has selective permeability to allow some salts to pass through according to the plant s need. 13- To prevent electric shock as wood doesn t allow electric current to flow though. 4-What is meant by: 1- They don t allow electricity to pass through such as wood, rubber and glass. 2- It is the fire produced as a result of placing electrical machines that produce heat near flammable materials such as curtains or rugs, not disconnecting these machines after use or operating many electrical machines using the same socket and it can be put off using sand instead of water. 3- It is composed of: dry cell (battery), lamp, electric wire and a switch. All must be connected to close the circuit and lighten the lamp. Page 1 of 12
4- It allows only some mineral salts to pass through the root hair s cell membrane according to the plant s need and it needs energy which is produced by respiration. 5-see fig(3-7) book page 83 6-. Force x force arm = resistance x resistance arm 100 x 25 = 500 x resistance arm Resistance arm = 100 x 25 / 500 = 5 cm Second ex. Page 94, 95 First Q. : 1- Electric conductors. 2- levers. 3- galaxies. 4- transpiration. Second Q. : 1- b 2- c 3-a Third Q.: 1- when one lamp is damaged the other lamps will turn off and the intensity of lamps will decrease by increasing the number of lamps. 2- Total lunar eclipse occurs. 3- Partial lunar eclipse occurs. Forth Q. : 1-2-x 3-x 4-5-x Fifth Q.: 1- High melting point and emits light when it is heated. 2- Inert gas to increase the life time of the filament. 3- Their shapes change to open and close the stoma 4- Water is electric conductor which increases the fire and harm the rescuer. Sixth Q.; 1- It is the result of a current passing through the human body, the harms resulted depend on the strength of the electric current and the time taken by the current to flow through the body. Page 2 of 12
2- It happens when the moon, the sun and the earth are on a straight line with the moon in the middle and it is found in a higher orbit from the earth so the shadow area will not reach the earth and the sun appears as a ring. 3- They are flying astronomical observatories that are provided with cameras and telescopes to study stars and galaxies from their locations outside the earth s atmosphere. The first on launched in an orbit is Sputnik. 4- They re groups of millions of stars forming beams of light in the dark space. They are different in shape. 5- It is the process by which the plant loses water in the form of water vapor from the leaves through stomata. 6- It is the property by which the cell membrane of the root hair allows some salts to pass according to the plant s need. First Q.; Third ex. p.96 1-Lever 2-rigid bar 3-first third 4-Edison 5-parallel 6-argon 7- coductors- insulators 8-electric shock 9-earth-sun-moon 10-spiral-four 11-sticky 12-slective permeability Second Q.: 1- second class of levers 2- law lever 3-filament 4-levers 5- series connection 6-electric insulators 7-partial lunar eclipse 8-galaxies 9-telescope 10-stomata 11- transpiration Third Q.: 1- If one lamp turns off, the others keep working and light intensity doesn t change 2- As the sun emits harmful ultraviolet and infrared radiations the harm the retina of the eye leading to temporarily blindness. 3- Because the resistance arm is always longer than the force arm so force is larger than the resistance. 4- To allow the flow of electricity. 5- To prevent electric shock as insulators don t allow electricity to pass through. 6- To prevent electric fires. 7- When the moon, the sun and the earth are on a straight line with the moon in the middle. 8- See q.3 p.97 9- To expose and direct the telescopes towards any part of the sky. 10- To find reasons for the astronomical phenomena happen in the sky. Page 3 of 12
Forth Q.: 1-x 2-x 3-4-x 5-x 6-x 7-8- 9-x 10-11- 12-13- 14-15- Fifth Q.: 1-c 2-b 3-a 4-c 5-b 6-b 7-c 8-b 9-d 10-c 11-c 12-b Sixth Q.: 1-second 2-inert 3-electric conductor copper wire 4-second 5-filaments 6- light 7-iron 8-18 years 9-annular 10-Galilleo 11-root hair 12-two guard cells 13- transpiration Seventh Q.: Points of comparison First class Second class Third class Definition Levers in which the fulcrum lies between the resistance and the force and they may conserve effort. Levers in which the resistance lies between the fulcrum and the force and they always conserve effort. Levers in which the force lies between the resistance and the fulcrum and they never conserve effort. Save effort Sometimes save effort Always save effort Never save effort. Points of comparison Series connection Parallel connection Light intensity Decreases by increasing the number of lamps Remains constant and is not affected by increasing or decreasing the number of lamps. Removing one lamp The other lamps will turn off The other lamps will keep working Electric conductors Materials that allow electricity to flow through. Ex: all metals, water, graphite, human body Electric insulators Materials that don t allow electricity to flow through. Ex: rubber, glass, wood, paper Total solar eclipse Formed in the shadow area (umbra) of the moon in which we cannot see the sun completely only sun corona appears. Total lunar eclipse Occurs when the whole moon enters the shadow area (umbra) of the earth. Page 4 of 12
Light bulb Structure: glass bulb filled with argon gas, tungsten filament, metal base connected to one or two pieces of lead. Fluorescent lamp Structure: glass tube filled with argon gas and little mercury and lined from inside with phosphoric material, two tungsten filaments one at each tip,two points of connection on each tip Direct injuries They are injuries that result from direct dealing with electricity such as electric fire, electric shock and electric burn Indirect injuries Injuries that result from falling from the ladder due to electric shock. Umbra area The real shadow area (cone shadow) formed when an opaque object totally blocks the light. Penumbra area The semi-shadow area where some light falls on it. Eighth Q.: 1) 1-b 2-c 3-a 4-g 5-d 2) 1-c 2-b 3-e 3) 1-c 2-b Ninth Question: What happens if: 1- We will not be able to perform many tasks such as saving effort or avoiding danger or increasing speed. 2- Astronomers will not be able to monitor movements of planets and moon, also they will not be able to study locations of stars. 3- The moon appears red and it is a total lunar eclipse. 4- Wrong question. 5- The lever will save effort. 6- It will not glow when heated. 7- The filament will burn. 8- It will cause many dangers such as electric shock or fire or burn. 9- Electricity will not flow and the lamp will not light. 10- They can cause electric shock. 11- It can cause blindness to him and affects his retina. Page 5 of 12
12- No transpiration process. 13- It creates a pulling force that raises water to the top of the plant. 14- The opening and closure of stoma will not be controlled and will not be able to control the water loss. 15- Water will not enter the root hair and epidermis. 16- Root hair will not be able to penetrate easily through soil particles. 17- Water will not enter by osmosis process. 18- The ball is close to the light source, the shadow area behind it is bigger than far from the Light source. 19- The fire will increase as water is an electric conductor. Tenth Question: First: 1- Light bulb. 2- Electric wire. 3- Positive pole. 4- Battery. Second: 1- Epidermis. 2- Cortex. 3- Endodermis. 4- Xylem. Third: 1- Penumbra. 2- Moon. 3- Sun. 4- Earth. Eleventh Question: Problems: 1- Resistance arm= force its arm resistance= 8 2 4= 4cm. 2- Resistance= force its arm resistance arm= 400 20 80= 100 N. 3- Resistance= force its arm resistance arm= 480 40 60 = 320 N. 4- Force arm= resistance its arm force = 200 20 400= 10 cm. Page 6 of 12
1- Write the scientific term: a- Fulcrum. b- Electric fire. c- Root hairs. d- Wrong question. 2- Put ( ) or ( ) and correct: a- ( ), it doesn t affect life on earth. Test (1) p. 111 b- ( ), aren t extinguished by water or are extinguished by sand. c- ( ) The leaves in plants are responsible for photosynthesis process. d- ( ) e- (X) if the force arm is longer. 3- Complete: a- Second. b- Electricity. c- Stoma. d- Resistance its arm. 4- Compare: a- Check p.64 and revision sheets. b- Good conductors of electricity: are materials that allow electricity to pass through.(water iron copper ) Electric insulators: are materials that don t allow electricity to pass through( rubber plastic wood ). 5- Give reason: 1- Because solar eclipse occurs when the umbra region of the moon falls on the earth s surface while lunar eclipse occurs when the moon enters the umbra region of the earth. 2- Because this can cause an electric fire. 3- As the fulcrum is in the middle. 4- Because the earth and moon are moving in fixed orbits with constant speed. 5- Resistance arm= force its arm resistance= 500 20 200 = 50cm. 6- Solar eclipse. Page 7 of 12
Q(1): a- 1 b- 1 c- 3 d- 4 e- 1 Q(2): Test (2) 1- To allow the penetration of water and salts through them. 2- Because sometimes the force arm can be longer than resistance arm in first class levers. 3- To protect the filament from burning as it is an inert gas. 4- Because water is an electric conductor. 5- To protect our eyes from the harmful ultraviolet and infrared rays that affects the retina. Q(3): A) What happens if: 1- It will not glow when heated. 2- He will have an electric shock. 3- Nothing will control the penetration of water and salts to the root hairs. B) Mention one function: 1- Changes electric energy to light energy. 2- Helps us to monitor movements of planets and moon, also it helps us to study locations of stars. Q4: a) What is the difference: 1- Total solar eclipse: all the sun is covered and we can see only the corona and you are in the umbra of the moon. Partial solar eclipse: part of the sun only is covered by the moon and you are in the penumbra of the moon. 2-3 rd class levers: never save effort while 2 nd class levers: always save effort. b) What s meant by: 1- Rigid bar that rotates around fixed point and affected by force and resistance. 2- The loss of water from the plants in the form of water vapour. 3- The type of injury happens when electricity pass through a human body. Q(5); 1- Human body is a good conductor of electricity. 2- We cannot see the sun completely in the partial eclipse. 3- The root hair absorb water and salts from the soil. 4- Galaxies are groups of millions of stars. 5- Stomata spread on the lower surface of the plants leaves. Page 8 of 12
Q(1): a- 2 b- 2 c- 1 Test (3) d- 2 e- 2 Q(2): 1- Because force arm is always longer than resistance arm. 2- To conduct electricity from the circuit to the lamp. 3- Because they are lost from time to time by the resistance of soil particles during root expansion. 4- Because the sun produces ultraviolet and infrared rays which harm the eye. 5- To allow the water to move from the soil to the root hair and epidermis by osmosis process. Q(3): A) What happens : 1- The transpiration process will not happen and water will not rise from the root to the top of the plant. 2- Filament will burn. 3- See Q2 P107. Q(4): B) What s meant by: 1- The fixed point that the lever rotates around. 2- Check Q4 p114. 3- The movement of water molecules from the higher water concentration to the lower water concentration through a semipermeable membrane. Q(5): 1- ( ) first class. 2- ( ) 3- ( ) has spiral shape and four arms. 4- ( ) collecting light. 5- ( ) Page 9 of 12
1) Choose: a- 1 b- 1 c- 2 d- 2 2) Write the scientific term: 1- Series connection. 2- Transpiration. 3- Galaxies. 4- Total lunar eclipse. 3) Put( ) or ( ): 1- ( ) thin. 2- ( ) lower surface. 3- ( ) Jupiter. 4- ( ) solar eclipse. 5- ( ) argon gas. 6- ( ) 4) Give reason: Test (4) 1- To help in the root penetration through soil particles. 2- So light intensity of lamps will not be affected by increasing number of lamps and if one lamp is burned the others are not affected. 3- As the arm of force is smaller than the arm of resistance and the force is greater than the resistance. 4- To protect the filament from burning. 5) See p43. 6) Resistance= force its arm resistance arm= 50 20 5 = 200N. Page 10 of 12
Test (5) First question: 1- Force resistance. 2- Effort force resistance force. 3- Direct- indirect. 4- Moon- earth. Second question: A) Write the scientific term: 1- Third class. 2- Total lunar eclipse. 3- Parallel connection. B)1- Lead piece. 2- base. 3- copper and lead wires. 4- glass bulb. 5- tungsten filament. Third question: A) Give reason: 1- To get rid of water in the form of water vapor by transpiration. 2- Because the earth is bigger than the sun so even if the moon is in a higher orbit, the earth s shadow will cover it. 3- Because force arm is longer than resistance arm. b) What s meant by: 1- Materials that allow electricity to pass through. 2- When sun, earth and moon are in one straight line with the earth in the middle and part of the moon enters the shadow area of the earth. Fourth question: A) Put( ) or ( ): 1- ( ) 2- ( ) 3- ( ) 4- ( ) 5- ( ) c) force its arm= 200 50= 10000 resistance its arm = 1000 10= 10000 as they are equal so this lever is balanced. Page 11 of 12
First question: 1- force fulcrum. 2- Moon-sun. 3- Galileo telescope. 4- Stomata- transpiration. Second question: 1- First class. 2- Galaxies. 3- Root. 4- Electric lamp. Third question: a) Give reason: Test(6) 1- Because force arm is shorter than resistance arm. 2- Because it is surrounded by thin membrane and contains concentrated salt solution that allow the osmosis process to happen. 3- To avoid having an electric shock as they don t allow electricity to pass through. b) What is meant by: 1- When the sun, earth and moon are in one straight line with the earth in the middle. 2- See q4 (b) P114 Fourth question: A) Put( ) or ( ): 1- ( ) 2- ( ) 3- ( ) short age. 4- ( ) Jupiter. c) force its arm = 500 10= 5000 resistance its arm= 200 20= 4000 as they are not equal so this lever is not balanced. Page 12 of 12