Formulas

Physics Formulas

1. Forces and Motion

• Newton's Second Law: $F = ma$

  • $F$ = force (N), $m$ = mass (kg), $a$ = acceleration (m/s²).

• Newton's Law of Universal Gravitation: $F = \frac{Gm_1 m_2}{r^2}$

  • G = 6.67 × 10^{-11} N·m²/kg², $r$ = distance between masses.

• Equations of Motion: $v = u + at$

$s = ut + \frac{1}{2}at^2$

$v^2 = u^2 + 2as$

• $u$ = initial velocity, $v$ = final velocity, $a$ = acceleration, $s$ = displacement, $t$ = time.

2. Energy, Work, and Power

• Work Done: $W = F \times d \cos \theta$

  • $F$ = force (N), d = displacement (m), θ = angle between force and displacement.

• Kinetic Energy: $E_k = \frac{1}{2} m v^2$

• Gravitational Potential Energy: $E_p = mgh$

  • $g = :highlight[9.8 m/s²]$.

• Power: $P = \frac{W}{t}$

  • Work done per unit time.

3. Electricity and Circuits

• Ohm's Law: $V = IR$

  • $V$ = voltage (V), $I$ = current (A), $R$ = resistance (Ω).

• Power in Circuits: $P = VI$

• Resistors in Series: $R_{total} = R_1 + R_2 + R_3 + ...$

• Resistors in Parallel: $\frac{1}{R_{total}} = \frac{1}{R_1} + \frac{1}{R_2} + \frac{1}{R_3} + ...$

4. Doppler Effect

$f' = \frac{v \pm v_o}{v \pm v_s} f$

• $f'$= observed frequency, $v$ = speed of sound, $v₀$ = velocity of observer, $vₛ$ = velocity of source.
• +ve for approaching, −ve for receding.

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Key Notes:

✔ Subscripts:

• 1 means "before", 2 means "after".

• o is for observer, s is for source in Doppler equations. ✔ Unit Conversions:

• To convert km/h to m/s, divide by 3.6.