📘 Grade 9 → Unit 3: Motion in a Straight Line
Distance, displacement, speed, velocity, acceleration, uniform motion, equations of motion.
📗 Grade 10 → Unit 2: Uniformly Accelerated Motion
Equations of motion, graphs of motion, free fall, relative velocity.
English: Displacement is a vector; distance is a scalar.
Average velocity = total displacement ÷ total time.
For constant acceleration: v = u + at, s = ut + ½at², v² = u² + 2as.
v = u + at | s = ut + 12at² | v² = u² + 2as
Velocity–time and Displacement–time graphs for uniformly accelerated motion
በጣም ግልፅ አማርኛ (ከEnglish ጋር):
Displacement = vector (አቅጣጫ አለው)። Distance = scalar (አቅጣጫ የለውም)።
ቋሚ acceleration ሲኖር ሦስቱ ቀመሮች፡
v = u + at፣ s = ut + ½at²፣ v² = u² + 2as።
“u = initial velocity, v = final velocity, a = acceleration, s = displacement, t = time.”
English: Newton’s 1st law: inertia. 2nd law: F = ma. 3rd law: action-reaction pairs.
Momentum p = mv. Conservation of momentum: total momentum before = total momentum after (if no external force).
F = ma | p = mv | FΔt = Δp (impulse)
በጣም ግልፅ አማርኛ (ከEnglish ጋር):
Newton’s 2nd law፡ F = ma (force = mass × acceleration)። Momentum p = mv። Impulse = FΔt = Δp።
External force ከሌለ momentum ይጠበቃል (conserved)።
“F = ma is the heart of dynamics. Action and reaction act on different bodies.”
F = ma, Newton’s three laws እና momentum conservation በentrance ላይ በጣም ብዙ ጊዜ ይመጣሉ!
3. Work, Energy እና Power
📘 Grade 9 → Unit 4: Force, Work, Energy, and Power
Work, kinetic energy, potential energy, power, conservation of energy.
English: Work W = Fd cosθ. Kinetic energy KE = ½mv². Gravitational potential energy PE = mgh.
Power P = W/t = Fv. Mechanical energy is conserved when only conservative forces act.
W = Fd cosθ | KE = 12mv² | PE = mgh | P = Wt
በጣም ግልፅ አማርኛ (ከEnglish ጋር):
Work W = Fd cosθ። Kinetic energy KE = ½mv²። Potential energy PE = mgh። Power P = W/t። Mechanical energy በconservative force ብቻ ሲኖር ይጠበቃል።
“Work is done only when force has a component along the displacement.” KE depends on speed squared.
📗 Grade 10 → Unit 1: Vector Quantities
Scalar vs vector, vector addition (triangle, parallelogram), resolution into components.
English: Scalars have magnitude only (mass, time, speed). Vectors have magnitude and direction (displacement, velocity, force).
Resultant of two perpendicular vectors: R = √(A² + B²). Components: Aₓ = A cosθ, Aᵧ = A sinθ.
📗 Grade 10 → Unit 4: Static and Current Electricity
Electric charge, Coulomb’s law, electric field, current, Ohm’s law, series and parallel circuits, electrical power.
English: Coulomb’s law: F = k|q₁q₂|/r². Ohm’s law: V = IR.
Series: same current, voltages add. Parallel: same voltage, currents add.
Power P = VI = I²R = V²/R.
V = IR | P = VI = I²R | F = k |q₁q₂|r²
በጣም ግልፅ አማርኛ (ከEnglish ጋር):
Ohm’s law፡ V = IR። Series፡ current ተመሳሳይ፣ voltage ይደመራል። Parallel፡ voltage ተመሳሳይ፣ current ይደመራል።
Power P = VI = I²R = V²/R።
“Series = same I, add V. Parallel = same V, add I.” Power: P = VI is the easiest starting point.
📗 Grade 10 → Unit 5: Magnetism
Magnetic field, force on a current-carrying conductor, electromagnetic induction (basic).
English: Force on a current in a magnetic field: F = BIL sinθ.
Faraday’s law: induced emf is related to rate of change of magnetic flux.
Right-hand rule for direction of force / field.
F = BIL sinθ | Φ = BA cosθ
በጣም ግልፅ አማርኛ (ከEnglish ጋር):
በmagnetic field ውስጥ ያለ current ላይ force፡ F = BIL sinθ። Faraday’s law፡ induced emf ከmagnetic flux ለውጥ ጋር ይገናኛል።
“Right-hand rule: fingers in B direction, thumb in I direction → palm pushes in F direction.”
F = BIL እና electromagnetic induction በentrance ላይ ብዙ ጊዜ ይመጣሉ!
7. Waves, Sound እና Light (Optics)
📘 Grade 9 → Unit 6: Mechanical Oscillation and Sound Wave
Oscillation, wave properties, sound waves.
📗 Grade 10 → Unit 6: Electromagnetic Waves and Geometrical Optics
EM spectrum, reflection, refraction, lenses, mirrors.
English: Wave speed v = fλ. Frequency f = 1/T.
Snell’s law: n₁ sinθ₁ = n₂ sinθ₂. Mirror/lens formula: 1/f = 1/v + 1/u.
Light: reflection (i = r), refraction (bending towards normal when entering denser medium).
v = fλ | n₁ sinθ₁ = n₂ sinθ₂ | 1f = 1v + 1u
በጣም ግልፅ አማርኛ (ከEnglish ጋር):
Wave speed v = fλ። Frequency f = 1/T። Snell’s law፡ n₁ sinθ₁ = n₂ sinθ₂።
Mirror/lens formula፡ 1/f = 1/v + 1/u።
“v = fλ is the universal wave equation.” For lenses: real is positive (sign convention carefully).
v = fλ, Snell’s law እና lens/mirror formula በentrance ላይ በጣም ብዙ ጊዜ ይመጣሉ!
8. Heat እና Temperature
📘 Grade 9 → Unit 7: Temperature and Thermometer
Temperature scales, heat transfer, specific heat capacity, change of state.
English: Q = mcΔT (heat to change temperature). Q = mL (heat to change state; L = latent heat).
Specific heat capacity c = heat needed to raise 1 kg by 1°C.
Heat flows from hot to cold.
English: Photoelectric effect: light ejects electrons from metal (Einstein). E = hf.
Radioactive decay: N = N₀ (½)^(t/T) where T is half-life.
Alpha, beta, gamma radiation differ in penetrating power and charge.
E = hf | N = N₀ (12)t/T
በጣም ግልፅ አማርኛ (ከEnglish ጋር):
Photoelectric effect፡ ብርሃን ከብረት electron ያስወጣል። E = hf። Half-life፡ የሬዲዮአክቲቭ ንጥረ ነገር ግማሽ ለመበስበስ የሚወስደው ጊዜ።
“Alpha = helium nucleus (least penetrating). Gamma = pure energy (most penetrating).”
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