Physics: IX Work, Energy and Power Study notes and CBSE Guess and Test Paper also download Numerical
Work : Product of magnitude of force and the magnitude of displacement of the body during time in which force acts is called work. Work is a scalar quantity. If W, F and s indicate work, force and displacement respectively then the work is given by the following formula. W = F s SI unit of work is newton metre (Nm) which is also known as joule in memory of famous physicist Joule. Thus, for work to be done, action of force is necessary as well as displacement in the direction of force is also necessary. What will be the work done if angle between the force and displacement is 900 ? Ans: work done is zero View full Paper Physics: IX Work, Energy and Power Also you may like WORK POWER ENERGY QUESTIONS & ANSWERS FOR CLASS XI CBSE View
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Q. a cube of mass 1kg with each side of 1cm is lying on the table. find the pressure exerted by the block on the table. take g=10 m/s2
Ans: Pressure is given as force/area so, Force, F = mg = 1000 X 981 gm.m/s2and area, A = 1x1 cm2 = 1 cm2Thus, the pressure exerted would be P = (981 X 1000) / 1 or P = 9.81 X 10 5 pa Q. The mass of a solid iron cube of side 3cm is to be determined usig a spring balance. If the of iron is approximately 8.5 g/cm3, the best suited spring balance for determining weight of the solid would be of 1. range 0-250gwt ; least count 1gwt 2. range 0-250gwt ; least count 5gwt 3. range 0-1000gwt ; least count 5gwt 4. range 0-1000gwt ; least count 10gwt Ans: Edge=3 cm , Density=8.5 g/cm3Mass= density x volume = 8.5 x(3x3)=229.5gwt Therefore second spring balance of range 0-250 gwt with least count 5gwt will be suitable. Q. The density of turpentine oil is 840 Kg/ m3. What will be its relative density. (Density of water at 4 degree C is 10 cube kg minus cube) Ans:Relative Density = Density of Substance/ Density of water at 4 0cDensity of turpentine oil = 840 kg/ m3 ( given).Density of water at 4 0c = 1000 kg/ m3Relative density of turpentine oil = Density of turpentine oil / Density of water at 4 0c= (840 / 1000 ) kg m-3/ kg m-3 = 0.84Since, the relative density of the turpentine oil is less than 1, therefore it will float in water. Q. A solid body of mass 150 g and volume 250cm3 is put in water . will following substance float or sink if the density of water is 1 gm-3? Ans: Visit link for full question solved for 9th CBSE board L. Lavoisier laid the foundation of chemical sciences by establishing two important laws of chemical combination.
Laws of Chemical Combination LAW OF CONSERVATION OF MASS ---- Lavoisier, states that ‘mass can neither be created nor destroyed in a chemical reaction.’ LAW OF CONSTANT PROPORTIONS --- This is also known as the law of definite proportions. This law was stated by Proust as “In a chemical substance the elements are always present in definite proportions by mass”. along with other scientists, noted e.g.In a compound such as water, the ratio of the mass of hydrogen to the mass of oxygen is always 1:8, whatever the source of water. Dalton’s atomic theory According to Dalton’s atomic theory, all matter, whether an element, a compound or a mixture is composed of small particles called atoms. The postulates of this theory may be stated as follows: (i) All matter is made of very tiny particles called atoms. (ii) Atoms are indivisible particles, which cannot be created or destroyed in a chemical reaction. (iii) Atoms of a given element are identical in mass and chemical properties. (iv) Atoms of different elements have different masses and chemical properties. (v) Atoms combine in the ratio of small whole numbers to form compounds. (vi) The relative number and kinds of atoms are constant in a given compound. Guess questions term-2 Science IX SUBJECT- PHYSICS
Q1: What is the relation between speed of sound, frequency and wavelength? Q2: Which travels faster sound of light, also discuss the speed of fastest one In solids, liquids and solids? Q3: A source of wave produces 20 crests and 20 troughs in 0.2s. Find the Frequency of the wave? Q4: Will a vibrating source always produce sound? Q5: What are supersonics, infrasonic and ultrasonic waves? Q6: Can sound waves travel through vacuum? Q7: Does the sound of a bomb explosion travel faster than the sound produced By a humming bee? Q8: If an observer places his ear at the end of a long pipe, he can hear two Distinct echoes when the pipe is hammered at the other end. Explain. Q9: A ship sends out ultrasound that results from the seabed and is detected After 3.42s. If the speed of ultrasound through sea water is 1531m/s. , what is the distance of the sea bed from the ship? Q10:What is density? Give its units. Q11: A force of 15N is uniformly distributed over an area of 150m2. Find pressure In Pascal? Q12: Differentiate between mass and weight? Q13: What is the relation between thrust and pressure? Q14: What is the relation between acceleration due to gravity and Gravitational Constant? Q15: What happens to a body when the density of a body is equal to the density of the liquid? Q16: A body of mass 2kg floats in a liquid, what is the buoyant force on the body? 17Q: A coolie carries a load of 50kg on his head and walks on a level road up to 100m.What is the work done by him? 18 Q: Give units of Power, Work and Energy? 19 Q: What is the commercial unit of energy? 20Q:Two bodies have their masses m1/m2 =3 and their kinetic energy E1/E2=1/3 .The ratio of their velocities are? 21Q:Prove that P=F * v , where P is power, F is force and v is velocity? 22Q:An electric motor creates a tension of 4500N in hoisting a cable and reels at a rate of 2m/s. The Power of the motor is? 23 Q: State Work Energy theorem? Test Paper Chapter 14, NATURAL RESOURCES
Q1. Why is the atmosphere essential for life? Q2. Why is water essential for life? Q3. How are living organisms dependent on the soil? Are organisms that live in water totally independent of soil as a resource? Q4. You have seen weather reports on television and in news paper. How do you think we are able to predict the weather? Q5. We know that many human activities lead to increasing levels of pollution of air, water bodies and soil. Do you think that isolating these activities to specific and limited areas would help in reducing pollution? Q6. Write a note on how forests influence the air, soil and water resources. Q7. What is ‘Water Cycle’ ? Explain the process of water cycle. Q8. Write a short note on ‘Nitrogen Fixation’ Q9.Explain the ‘Nitrogen Cycle Q10. Discuss the consequences of the increase in the concentration of Carbon dioxide and other Green House gases in the atmosphere CBSE Summative & Formative Assignment based on CCE Test Paper Biology Term-2 CCE Test Paper Biology Chapter Natural Resources ix Biology-1 Download File CCE Test Paper Biology Chapter Natural Resources ix Biology-2 Download File CBSE NCERT Class 9th natural resources Solved Board Questions Download File |
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