Q. 01. A ball hits a wall horizontally at 6m/s. It rebounds horizontally at 4.4m/s. The ball is in contact with the wall for 0.04s. What is the acceleration of the ball?
Solution: Initial velocity(u) = 6.0m/s Final velocity(v) = -4.4 m/s (because direction of ball has become opposite) time = 0.04 s thus, acceleration (a) = (v-u)/t a= [-4.4 – 6.0]/ 0.04 a= (-10.4)/0.04 after multiplying -10.4/0.04 by 100/100 (to make calculations simpler), we get a= -1040/4 = -260 m/s2 Q.02. A cheetah is the fastest land animal and it can achieve a peak velocity of 100 km per hour up to distances less than 500 metres. If the cheetah spots his prey at a distance of 100 meters what is the minimum time it will take to get its prey? Solution: If the cheetah spots the prey at its top speed, the cheetah will hunt down the prey with the speed of 100 km/h. = 27.7 m/s Now, time = d/s = 100/27.7 = 3.6 sec. So, the minimum time the cheetah will take to get the prey is 3.6 s. Q.03. A police jeep is chasing velocity of 45 km/h. A thief in another jeep moving with a velocity of 153 km/h. police fires a bullet with muzzle velocity of 180 m/s the velocity it will strike the car of the thief is? Solution: Given: Velocity of police jeep = 45 m/hr = 12.5 m/s Velocity of thief’s jeep = 153 km/hr = 42.5 m/s Velocity of bullet = 180 m/s Now, since bullet is fired from police jeep which is going at 42.5 m/s, Therefore, velocity of bullet is (180 + 12.5) = 192. 5 m/s. To calculate velocity with which bullet with hit the thief we use concept of relative velocity. Therefore, we have VBT = VB - VT Here VB is velocity of bullet and VT is velocity of thief VBT = 192. 5m/s - 42.5 m/s = 150m/s Q. 05. A car is travelling at 20 m/s along a road. A child runs out into the road 50 m ahead and the car driver steps on the brake pedal. What must the car’s deceleration be if the car is to stop just before it reaches the child? Solution: u = 20m/s ; s = 50m and v = 0m/s Using, V^2 = u^2 + 2as a = (v^2 – u^2)/2s a = (0^2 - 20^2)/(2 x 50) = - 4m/s^2 Acceleration = -4 m/s2 or, retardation = 4 m/s2 Full paper Download More related material VISIT: Motion and Rest
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Q. 26. How is pressure developed in a container full of a gas ?
Gaseous molecules are free to move in the container. The molecules collide with each other and with the wall of the container. On the wall the molecules exert force. The force per unit area is called the pressure of the gas. Q. 27. What are the applications of interconversion of states of matter ? The inter conversion of states of matter is used to : (i) generate electricity in thermal power plant. (ii) separate nitrogen and oxygen from air by liquefaction. (iii) prepare machine parts. (iv) prepare room fresheners. (v) prepare ice-creams. Q.28. What happens to a gas if its inter molecular space is reduced ? If the inter molecular distance between molecules of a gas is reduced, it changes to liquid. Further reduction it is changed to solid. Q. 29. Which of the following substances is most compressible?CO2, H2O, NaCl. Answer: CO2 Q. 30. Which property of a gas results in steady pressure of the gas ? Answer: The constant bombardment of the gas molecules with the walls of the container Q. 31. In which of the following substances, weakest inter molecular force is expected: H2O, CH3OH, Answer: Al, He. He Q. 32. One gas mixes with another gas easily. What is this property called ? Answer: Diffusion. Q. 33. Describe briefly (i) Melting point and (ii) Boiling point. Answer: (i) Melting point :- The melting point of a solid is that temperature at which it changes into the liquid. From the beginning to the end of melting, the temperature does not change. (ii) Boiling point :- The boiling point of a liquid is that temperature at which a liquid starts boiling at the atmospheric pressure. Q. 34. How would you find out whether a sample of sodium chloride is pure or impure ? Answer: Pure substance melts at its melting point. If sodium chloride melts at 97ºC,then the sample is pure otherwise impure. Q. 35. How will you find out whether a sample of water is pure or impure ? Answer: The boiling point of water at one atmospheric pressure is 100ºC. If the given sample of water boils at 100ºC then it is pure otherwise impure. Q. 36. Why do solids have a fixed shape and gases have neither a fixed shape nor a fixed volume ? Answer: In solids the molecules are close due to intermolecular force. The molecules are arranged in a fixed pattern. The movement of molecules are not possible. Hence its shape are fixed . In gases the intermolecular force are negligible. Molecules are free to move in any direction. The distance between the molecules is very large. Hence gases do not have fixed shape and fixes volume. Q. 37. What is Vaporization ? Answer: The change of liquid into its gaseous form (vapour) when temperature of liquid is increased is called vaporization. Q. 38. What is Sublimation ? Answer: A change of state directly from solid to gas without changing into liquid state or vice-versa is called sublimation. Q. 39. What is Condensation ? Answer: A change of gaseous state to liquid state or solid state is called condensation. Q. 40. What is Deposition ? Answer: A change of vapour to solid is called deposition. It is the reverse process of sublimation Q. 41. What is Liquefaction ? Answer: A substance which is gas in normal condition, when changed to liquid by cooling it under pressure is called liquefaction. Q. 42. What is Solidification ? Answer: A substance which is a liquid in normal condition, when changed to solid to by cooling it under pressure is called solidification. Q. 43. What is difference between vapour and gas. Answer: Vapour is used to denote the gaseous state of fluids which exists as liquids under normal conditions, while gas is used to denote the gaseous state at normal temperature. We always speak water vapour and carbon dioxide gas. Q. 44. Why do the three states of matter differ ? Answer: The three states of matter differ due to : (i) Difference in packing and arrangement of molecules in the three states. (ii) Intermolecular force of attraction are different in the three states. Q. 45. Why does the temperature remain constant until whole of the solid changes into liquid, though the heat energy is constantly supplied ? Answer: During melting, temperature of the liquid phase remains the same as that of the liquid phase. The heat energy supplied is utilized to destroy the crystal pattern and is stored in the liquid phase as potential energy. Q. 46. Why does the temperature remain constant during boiling though heat is constantly supplied ? Answer: The heat energy supplied is utilized to destroy the intermolecular force amongst the molecules of the liquid and is stored as potential energy. Q. 47. Why does a gas fill a vessel completely ? Answer: The molecules of a gas are moving continuously with a high speed in all direction and intermolecular force amongst the molecules are negligible. Hence it fills the vessel completely. Q. 48. How does the state of matter changes from solid to liquid and then to gas on heating ? Answer: In solids particles are very close. When heat is given to solid, the distance between particles increases and it takes the shape of the container. On further heating the distance between the particles increases in such an extent that the molecules are free to move. This is a gaseous state. Q. 49. Explain the term boiling on the basis of kinetic theory of gases. When a liquid is heated up to its boiling point, the heat is absorbed by the molecules and stored in the form of potential energy . When potential energy of the molecule is is increased, the intermolecular distance is increased. It means intermolecular force of attraction reduces to zero. The molecules start escaping in air causing the liquid to boil. Q. 50. Explain the term melting on the basis of kinetic theory. Answer: The molecules of solids vibrate about its mean position. When it is heated, its kinetic energy is increased and it starts vibrating vigorously. At the melting point the intermolecular force of attraction is reduced and particles can not hold each other with strong force to hold them in their fixed position. The crystalline structure is destroyed and it starts melting. Matter in our surrounding solved questions class9 Step-01 Read_Download 1 marks questions (very short answer type question)
Q.1:- Name a metal which can be cut with a knife? Ans:- sodium Q.2:- Which metal is the best conductor of electricity? Ans:- silver Q.3 Which metal is poorest conductor of electricity? Ans:- iron Q.4 Which metal is most ductile? Ans.:- gold Q.5 Which metal is best conductor of heat ? ans:- silver(and copper) Q.6:- Which metal other than mercury is liquid at room temperature? Ans:- Gallium Q.7:- Which metal is poorest conductor of heat? Ans:- lead (and mercury) Q.8:- What is the nature of oxides of metal? Ans:- Basic Q.9:- What is the nature of oxides of non- metal? Ans:-Acidic Q10:-Which non-metal conduct electricity? Ans:-Graphite, allotrope of carbon conduct electricity. Q.11:- Which non-metal is lusturous? Ans:- iodine Q.12:- Why metals are hard and have high melting point? Ans:- Because of their crystalline structure metals are hard. Q.13:- What is an amalgam? Ans:- An alloy of two metals in which one is mercury is called amalgam. Q.14:- What are the constituents of solder? Ans:- tin and lead Q.15:- Name the green coloured compound which appears on the surface of copper utensils? Ans:- Basic copper carbonate 2 marks questions (short answer type question) Q.1:- What are amphoteric oxides? Give an example. Ans:- Oxides which react with both acids as well as bases to produce salt and water are called amphoteric oxides .for example:- Al2O3 . ZnO Q.2:- Name two metals that react with dil.HNO3 to evolve H2 gas ? Ans:- magnesium and manganese Q.3:- Why metals like potassium and sodium catch fire when treated with water? Ans:- The reaction between sodium and water is so violent that the H2 gas released catches fire . Reaction:- 2Na(s) + 2H2O(l) ----------> 2NaOH(aq) + H2(s) + heat energy Q.4:- Why sodium is kept immersed in kerosene oil? Ans:- This is because sodium react with air to form Na2O (sodium oxide). Q.5:- Which gas is produced when dil. HCl is added to a reactive metal? Write the chemical reaction when iron reacts with dil. H2SO4? Ans:- Hydrogen gas is produce when dil. HCl is added to a reactive metal. Fe(s) + H2SO4(dil.) ------> FeSO4(aq) +H2(g) Q.6:- What would you observe when zinc is added to a solution of iron(II) sulphate ?write the chemical reaction that takes place. Ans:- The solution of iron(II)sulphate slowly turns to colourless and grey coloured layer of Fe is deposited on the surface of zinc metal. Zn(s) + FeSO4(aq) -------> ZnSO4(aq) + Fe(s) Q.7:- Why the item made of silver turns black when exposed to air? Ans:- Hydrogen sulphide present in air react with silver and form silver sulphide which provide black colour to silver Ag + H2S ------> Ag2S Q. 8:- Why ionic compounds have high melting points? Ans:- Ionic solids have crystalline structure in which there is strong interionic attraction. So large amount of energy is needed to overcome this force of attraction. Q. 9:- What do you mean by roasting? How it is different from calcination? In which types of ores roasting is done? Ans:- Heating an ore strongly in excess of air is called roasting. This is done to convert sulphide ores into its oxide form. Calcination is different from roasting because it is done in absence of air. 2ZnS(s) + 3O2(g) heat -------> 2ZnO(s) + 2SO2 Q10:- Define :- (i) Ore, (ii) Mineral. Ans:- Ore:- The minerals from which an element can be extracted profitably and conveniently is called ore. E.g. - Bauxite, Al2O3.2H2O – is an ore of aluminum. Mineral:- The compounds of elements that occurs naturally in earth‘s crust are called minerals. E.g.- Glauber‘s salt Na2SO4.7H2O; Borax Na2B4O7.10H20 are two mineral sources of Sodium. Q.11:- Name two metals which are found in nature in the free state. Ans:- Silver and Gold. Q.12:- Define :- (i) Enrichment of Ores (ii) Gangue. Ans:- (i) Removal of earthly impurities like sand, clay from an ore is called enrichment of ore. (ii) The earthy impurities like sand, clay that are found along with an ore are called gangue or matrix. Q.13:- Write short notes on electrolytic refining of metals. Ans:- In electrolytic refining the impure metal is taken as anode and the pure metal is taken as cathode. These two rods are dipped in aqueous salt solution of the same metal and electricity is passed. Pure metal from anode is dissolved into the solution and equivalent amount of pure metal from the electrolyte is deposited at the cathode Q.14:- Name the conditions which are essential for corrosion. Ans:- (i) Presence of moisture, (ii) Presence of air. Q.15:- What is Galvanisation? Write its use. Ans:- Galvanisation is a method of protecting steel and iron from rusting by coating them with a thin layer of Zinc. Short Answer Type Questions:- (3 marks) Q.1:- Write suitable example, explain how a metal low in the activity series can be extracted? Ans:- Metals low in the activity series are less reactive. The oxides of these metals can be reduced to metals by heating alone. For example, extraction of Mercury (Hg) from Cinnabar (HgO). 2HgS(s) + 3O2(g) heat---------> 2HgO(s) + 2SO2(g) 2HgO(s) heat ----------------> 2Hg(l) + O2(g) Q.2:- Write three properties of ionic compounds. Ans:- (i) Ionic compounds have high melting points. (ii) Ionic compounds are soluble in water. (iii) Ionic compounds conduct electricity in aqueous and molten state. HOTS 1. What is anodizing? What is its use? Ans. The process of forming a thick oxide layer of aluminium oxide that makes it resistant to further corrosion. 2. What is aqua regia? What is its use? Ans. Aqua regia is a mixture of conc. HCl and conc. HNO3 in the ratio 3:1. It can dissolve gold and platinum. 3. What do you mean by thermite reaction? What is its use? Ans. The reaction between Iron(II) oxide Fe2O3 with Al is used to join rail track joints or cracked machine parts. This reaction is known as thermite reaction. Fe2O3 (s) + 2Al (s) 2Fe (l) + Al2O3 (s) + Heat 4. Why active metals do not liberate H2 gas when treated with dil. HNO3? Ans. This is because HNO3 is strong oxidizing agent. It oxidizes H2 produced to water and itself gets reduced to nitrogen oxides. 5. Sometimes the ore itself acts as a reducing agent. Give an example. Ans. During roasting of Cu2S, the ore itself acts as a reducing agent. 2CuS (s) + 3O2(g) → 2Cu2O(s) + 2SO2(g) 2Cu2O + Cu2S → 6Cu(s) + SO2(g) For more study material and Pdf material : Metal and Non Metal 1 MARKS QUESTIONS
1. A farmer floods his field everyday thinking that watering in this manner will result a better yield of his wheat crop. What will be the result of this action of the farmer. Ans.This will result in water logging of the soil due to which roots cannot breathe and ultimately plants will die . 2. Name the term for transport of food from leaves to other parts of plants. Ans.Translocation 3. Which pancreatic enzyme is effective in digesting proteins? Ans.Trypsin 4. Which enzyme is present in saliva breaks down starch? Ans.Salivary amylase. 5. After a vigorous exercise you may experience cramps in your leg muscles. Why does this happen? Ans. Accumulation of lactic acid 6. Name the organelle in which photosynthesis occurs. Ans.Chloroplast. 7. Name the type of blood vessels which carry blood from organs to the heart. Ans.Veins. 8. Name the respiratory structures of i.Mosquito ii)earth worm. Ans.i) mosquito—System of air tubes. ii)earth worm—moist skin. 9. Write the two functions of kidneys. Ans.Osmoregulation and excretion. 10. What are spiracles. Ans The holes found on the lateral side of insect‘s body. 2 marks questions answer 1.Differentiate autotrophs and heterotrophs. Ans.The organism which prepare their own food are called autotrophs for eg: green plants . The organisms which depend on the food prepared by other organisms are called heterotrophs for eg: animals 2.Differentiate between aerobic respiration and anaerobic respiratrion. Ans. Aerobic respiration It occurs in the presence of oxygen Glucose is completely broken down to carbon dioxide and water. More energy is released 38 ATP. Anaerobic respiration It occurs in the absence of oxygen. Glucose is incompletely oxidised to ethanol or lactic acid Less energy is produced 2ATP 3. Explain the role of the following in the process of digestion in the human body A) saliva B) trypsin Answer: a) Saliva contains an enzyme salivary amylase which digests starch b) trypsin.-helps in digestion of proteins. 4. What is double circulation.? Ans..In double circulation blood goes through the heart twice during each cycle in vertebrates. 5 Write any two points of difference between respiration in plants and respiration in animals. Respiration in plants.
Respiration in animals
6 Differentiate Holozoic nutrition and saprophytic nutrition. Answer: Holozoic nutrition In this nutrition organisms derive their food by consuming complex organic materials by the process of ingestion and then converting the complex molecules into simpler ones to obtain nutrients. Eg. animals and human beings. Saprophytic nutrition In this type of nutrition organism derive their food from the dead and decaying materials. Eg.fungi 7. Why do veins have thin walls compared to arteries? Ans: Veins do not have thick walls because blood is no longer under pressure but blood emerges from the heart under high pressure. So arteries have thick walls 8. Where do the plants get each of the raw materials? a) CO2 b) water c) minerals Ans. a) CO2 from air, b)water-from soil c)minerals-from soil along with water. 9. What do the following transport? a)xylem b phloem c) pulmonary vein d) venacava Ans. a) xylem-water and minerals b) phloem- prepared food. c) Pulmonary vein-oxygenated blood d) vena cava -deoxygenated blood 10. Write one function each of the following components of transport system in human beings. a)arteries b) veins c)capillaries ans: (a) arteries- carry blood from heart to different parts of body (b) veins-carry blood from different parts of body to the heart. c) Capillaries-exchange of material between blood and surrounding cells. 11. a) How is fat digested in our body? b) Where does this take place? Ans. A) fats are emulsified by bile salts. The emulsified fats are acted upon by pancreatic and intestinal lipase to form fatty acids and glycerol. b) digestion of fats occurs in small intestine. 3 MARKS QUESTIONS 1. What is the function of epiglottis in man? Draw a labeled diagram showing the human respiratory system. Epiglottis. It is an adjustable flap of fibro cartilage that covers glottis when food is being swallowed. Diagram of human reaspiratory system. Fig 6.9 (NCERT text book page no.104.) 3. What is known as double circulation Briefly explain the process . Ans.It is passage of the same blood twice through the heart first on the right side, then on the left side in order to complete one cycle. It has two components ,pulmonary circulation and systemic circulation. Hint. pulmonary circulation and systemic circulation 4.How water is transported upwards in plants? Answer: Transpiration in leaves creates pull force and osmosis creates push fore. These two forces together helps in the movement of water and minerals dissolved the leaves. 5. Name the tissue that transports the prepared food in plants . Explain the mechanism of transport of food in plants. Ans.: phloem Hint: translocation using energy from ATP. 6Briefly describe the excretory system in human beings. Hint a pair of kidneys a pair of ureters,a urinary bladder and a urethra. 7. Describe the functioning of nephrons. Ans: Functioning of Nephron (i). Filtration: Filtration of blood takes place in Bowman’s capsule from the capillaries of glomerulus. The filtrate passes into the tubular part of the nephron. This filtrate contains glucose, amino acids, urea, uric acid, salts and a major amount of water. (ii) Re-absorption: As the filtrate flows along the tubule useful substances such as glucose, amino acids, salts and water are selectively re-absorbed into the blood by capillaries surrounding the nephron tubule. The amount of water re-absorbed depends on the need of the body and also on the amount of wastes to be excreted. (iii) Urine: The filtrate which remains after re-absorption is called urine. Urine contains dissolved nitrogenous waste, i.e. urea and uric acid, excess salts and water. Urine is collected from nephrons by the collecting duct to carry it to the ureter. 8.What are the differences between the transport of materials in xylem and phloem hint transport in xylem: Ans: water transport using transpirational pull Transport in phloem: food, transport using energy from ATP 9. Lymph is another type of fluid involved in transportation. Justify the statement by two reason. Ans: 1. It drains tissue fluid from the extra cellular space back into blood. 2. it takes lymphocytes and antibodies from the lymph nodes to the blood. 3. Some of the fluid from digestive tract is absorbed in the lymph and store the fluid Temporarily. 10. differentiate between osmoregulation and excretion excretion is the elimination of metabolic waste products from the body. Ans: Osmoregulation is regulating osmotic pressure of the body fluids by controlling the amount of water and salts in the body 11. What is the function of liver in human body ans. : Liver. Secretes bile that emulsifies fats . Bile provide alkaline medium for digestion of proteins. For more study visit Life process extra score ![]() CLASS 10TH SCIENCE STUDY HELP BY JSUNIL Science is a subject that often encourages exploration to learn. It is also a subject that gives lot of scope to learn by way of practical knowledge. Students in class 9 are intrigued by the various topics that are presented to them. One of the best ways to prepare for the upcoming exams is by reviewing the previous year’s question papers and sample papers. The CBSE sample papers class 9 science 2014 helps students by giving a peek into the pattern of the question paper and test their understanding of the concepts learn in the classroom. ============================================================= Solved Questions Class X Acid Base and Salt HOTS with solution Download File Acid Base and Salt Solved Question Paper-1 Download File Acid Base and Salt Solved Question Paper-2 Download File Acid Base and Salt Solved Question Paper-3 Download File 10th Science NCERT solutions Acid Base and Salt Download File ============================================== For further study material visit page: Acid bases and salt for class 10 |
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