Physics Form 2

Yaliyomo

1. 1. Static Electricity

   Majaribio 1 Maswali 15

   Maelezo ya mada

   • Electric charge and charging by friction
   • Forces between charges, conductors and insulators
   • Charging by induction and by contact
   • The gold-leaf electroscope
   • Charge distribution, lightning and applications
   • Summary

   Electric charge All matter is made of atoms. An atom has a central nucleus containing positively charged protons and uncharged neutrons , with negatively charged electrons moving around it. A normal atom has equal numbers of protons and electrons, so it is neutral . A body becomes charged when it gains or loses…

2. 2. Current Electricity

   Majaribio 1 Maswali 15

   Maelezo ya mada

   • Electric current and simple circuits
   • Circuit symbols and circuit diagrams
   • Potential difference, e.m.f. and cells
   • Resistance and Ohm's law
   • Resistors in series and in parallel
   • Summary

   Electric current Electric current is the rate of flow of electric charge: I = Q ÷ t . Its SI unit is the ampere (A) ; 1 A = 1 C/s. In metal wires the charge carriers are electrons, which move from the negative terminal to the positive terminal. By convention, conventional current is taken to flow from positive to…

3. 3. Magnetism

   Majaribio 1 Maswali 16

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   • Magnets and the law of magnetism
   • The domain theory of magnetism
   • Making and destroying magnets
   • Magnetic fields
   • The Earth's magnetism
   • Summary

   Magnets and magnetic materials A magnet is a body that attracts magnetic materials such as iron, steel, nickel and cobalt. These are called ferromagnetic or magnetic materials. Materials such as copper, aluminium, wood, plastic and glass are non-magnetic . Natural magnets are made of a rock called lodestone…

4. 4. Forces in Equilibrium

   Majaribio 1 Maswali 15

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   • The moment of a force
   • The principle of moments
   • Conditions of equilibrium
   • Centre of gravity
   • Stability and states of equilibrium
   • Summary

   Moment of a force A force can make a body turn about a fixed point called the pivot (or fulcrum). The turning effect of a force is called its moment : Moment = force × perpendicular distance from the pivot to the line of action of the force The SI unit is the newton metre (N m) . A larger force or a longer distance…

5. 5. Simple Machines

   Majaribio 1 Maswali 16

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   • Machines: mechanical advantage, velocity ratio and efficiency
   • Levers and their three classes
   • Pulleys
   • The inclined plane and the wheel and axle
   • The screw, gears and improving efficiency
   • Summary

   What is a machine? A machine is a device that makes work easier by allowing a small force (the effort ) to overcome a larger force (the load ), or by changing the direction or point of application of a force. Examples: levers, pulleys, inclined planes, wheel and axle, screws and gears. A machine never gives out more…

6. 6. Motion in a Straight Line

   Majaribio 1 Maswali 16

   Maelezo ya mada

   • Distance, displacement, speed and velocity
   • Acceleration and the ticker-timer
   • Equations of uniformly accelerated motion
   • Motion graphs
   • Motion under gravity
   • Summary

   Distance and displacement Distance is the total length of path travelled; it is a scalar (size only). Displacement is the distance moved in a stated direction from the starting point; it is a vector (size and direction). Both are measured in metres. If you walk 300 m to a shop and back, distance = 600 m but…

7. 7. Newton's Laws of Motion

   Majaribio 1 Maswali 15

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   • Inertia and Newton's first law
   • Momentum and Newton's second law
   • Impulse and safety
   • Newton's third law of motion
   • Conservation of momentum and collisions
   • Summary

   Inertia and Newton's first law Inertia is the tendency of a body to remain at rest or, if moving, to continue moving with uniform velocity. Mass is a measure of inertia: a loaded lorry is harder to start and to stop than a bicycle. Newton's first law : a body continues in its state of rest or of uniform motion in a…

8. 8. Temperature

   Majaribio 1 Maswali 15

   Maelezo ya mada

   • Heat and temperature
   • Temperature scales and fixed points
   • Liquid-in-glass thermometers and calibration
   • The clinical thermometer and other thermometers
   • Summary

   Heat and temperature Temperature is the degree of hotness or coldness of a body. It is related to the average kinetic energy of the particles of the body. Heat is the energy that flows from a hotter body to a colder one because of their temperature difference. Heat is measured in joules; temperature in kelvin (K) or…

9. 9. Sustainable Energy Sources

   Majaribio 1 Maswali 15

   Maelezo ya mada

   • Energy sources and sustainability
   • Solar energy
   • Wind and hydro energy
   • Biomass, biogas, geothermal and tidal energy
   • Saving energy and using it efficiently
   • Summary

   What is sustainable energy? Sustainable energy is energy obtained from sources that can meet today's needs without harming the ability of future generations to meet theirs. Such sources are usually renewable (naturally replaced) and cause little pollution. Non-renewable sources – coal, oil, natural gas and nuclear…