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PART 1 INTERACTION OF MATTER, SPACE & TIME
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Concepts of Matter
Simple structure of matter should be discussed. Three physics states of matter, namely solid, liquid and gas should be treated. Evidence of the particle nature of matter e.g. Brownian motion experiment, Kinetic theory of matter. Use of the theory to explain; states of matter (solid, liquid and gas), pressure in a gas, evaporation and boiling; cohesion, adhesion, capillarity. Crystalline and amorphous substances to be compared (Arrangement of atoms in crystalline structure to be described e.g. face centred, body centred.
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Fundamental and derived quantities and units
Length, mass, time, electric current luminous intensity, thermodynamic temperature, amount of substance as examples of fundamental quantities and m, kg, s, A, cd, K and mol as their respective units. Volume, density and speed as derived quantities and m3, kgm-3 and ms-1 as their respective units.
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Position, distance and displacement
Position of objects in space using the X,Y,Z axes should be mentioned. Use of string, metre rule, vernier calipers and micrometer screw gauge. Degree of accuracy should be noted. Metre (m) as unit of distance. Use of compass and a protractor. Graphical location and directions by axes to be stressed.
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Mass and weight
Use of lever balance and chemical/beam balance to measure mass and spring balance to measure weight. Mention should be made of electronic/digital balance. Kilogram (kg) as unit of mass and newton (N) as unit of weight.
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Time
The use of heart-beat, sand-clock, ticker-timer, pendulum and stopwatch/clock. Second(s) as unit of time.
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Fluid at rest
Experimental determination for solids and liquids. Concept and definition of pressure. Pascal’s principle, application of principle to hydraulic press and car brakes. Dependence of pressure on the depth of a point below a liquid surface. Atmospheric pressure. Simple barometer, manometer, siphon, syringe and pump. Determination of the relative density of liquids with U-tube and Hare’s apparatus. Identification of the forces acting on a body partially or completely immersed in a fluid. Use of the principle to determine the relative densities of solids and liquids. Establishing the conditions for a body to float in a fluid. Applications in hydrometer, balloons, boats, ships, submarines etc.
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Motion
Only qualitative treatment is required. Illustration should be given for the various types of motion. Numerical problems on co-linear motion may be set. Force as cause of motion. Push and pull These are field forces namely; electric and magnetic attractions and repulsions; gravitational pull. Frictional force between two stationary bodies (static) and between two bodies in relative motion (dynamic). Coefficients of limiting friction and their determinations. Advantages of friction e.g. in locomotion, friction belt, grindstone. Disadvantages of friction e.g reduction of efficiency, wear and tear of machines. Methods of reducing friction; e.g. use of ball bearings, rollers, streamlining and lubrication. Definition and effects. Simple explanation as extension of friction in fluids. Fluid friction and its application in lubrication should be treated qualitatively. Terminal velocity and its determination. Experiments with a string tied to a stone at one end and whirled around should be carried out to (i) demonstrate motion in a Vertical/horizontal circle. (i) show the difference between angular speed and velocity. (ii) Draw a diagram to illustrate centripetal force. Banking of roads in reducing sideways friction should be qualitatively discussed.
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Speed and velocity
Metre per second (ms-1) as unit of speed/velocity. Ticker-timer or similar devices should be used to determine speed/velocity. Definition of velocity as ∆ s ∆t. Determination of instantaneous speed/velocity from distance/displacement-time graph and by calculation. Unit of acceleration as ms-2 Ticker timer or similar devices should be used to determine acceleration. Definition of acceleration as ∆ v ∆t . Determination of acceleration and displacement from velocity-time graph Use of equations to solve numerical problems.
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Scalars and vectors
Mass, distance, speed and time as examples of scalars. Weight, displacement, velocity and acceleration as examples of vectors. Use of force board to determine the resultant of two forces. Obtain the resultant of two velocities analytically and graphically. Torque/Moment of force. Simple treatment of a couple, e.g. turning of water tap, corkscrew and steering wheel.) Use of force board to determine resultant and equilibrant forces. Treatment should include resolution of forces into two perpendicular directions and composition of forces Parallelogram of forces. Triangle of forces. Should ne treated experimentally. Treatment should include stable, unstable and neutral equilibra. Use of a loaded test-tube oscillating vertically in a liquid, simple pendulum, spiral spring and bifilar suspension to demonstrate simple harmonic motion.
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Simple harmonic motion
Relate linear and angular speeds, linear and angular accelerations. Experimental determination of ‘g’ with the simple pendulum and helical spring. The theory of the principles should be treated but derivation of the formula for ‘g’ is not required Simple problems may be set on simple harmonic motion. Mathematical proof of simple harmonic motion in respect of spiral spring, bifilar suspension and loaded test-tube is not required.
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Newton’s laws of motion:
Distinction between inertia mass and weight Use of timing devices e.g. ticker-timer to determine the acceleration of a falling body and the relationship when the accelerating force is constant. Linear momentum and its conservation. Collision of elastic bodies in a straight line. Applications: recoil of a gun, jet and rocket propulsions.
Distinction between mass and weight
The broadest definition of weight in this sense is that the weight of an object is the gravitational force on it from the nearest large body, such as Earth, the Moon, the Sun, and so on. This is the most common and useful definition of weight in physics. It differs dramatically, however, from the definition of weight used by NASA and the popular media in relation to space travel and exploration. When they speak of “weightlessness” and “microgravity,” they are really referring to the phenomenon we call “freefall” in physics. We shall use the above definition of weight, and we will make careful distinctions between free-fall and actual weightlessness.
It is important to be aware that weight and mass are very different physical quantities, although they are closely related. Mass is the quantity of matter (how much “stuff”) and does not vary in classical physics, whereas weight is the gravitational force and does vary depending on gravity.
It is tempting to equate the two, since most of our examples take place on Earth, where the weight of an object only varies a little with the location of the object. Furthermore, the terms mass and weight are used interchangeably in everyday language; for example, our medical records often show our “weight” in kilograms, but never in the correct units of newtons.
When the net external force on an object is its weight, we say that it is in free-fall. That is, the only force acting on the object is the force of gravity. In the real world, when objects fall downward toward Earth, they are never truly in free-fall because there is always some upward force from the air acting on the object.
The acceleration due to gravity g varies slightly over the surface of Earth, so that the weight of an object depends on location and is not an intrinsic property of the object. Weight varies dramatically if one leaves Earth’s surface. On the Moon, for example, the acceleration due to gravity is only 1.67 m/s^2 . A 1.0-kg mass thus has a weight of 9.8 N on Earth and only about 1.7 N on the Moon.
Use of beam balance to measure mass and weight:
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