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CSEC Physics Formula Sheet

Your Complete Reference Guide

Essential Understanding: This formula sheet contains all the key equations you need for CSEC Physics examinations. Use it as a quick reference for homework, test preparation, and exam review. Remember: understanding when and how to use each formula is just as important as memorizing it!

✅ 50+ Formulas Across all topics

📚 Exam Ready CSEC aligned

💡 Memory Tips Included

📊 Quick Topic Overview

⚙️ Mechanics

Motion, forces, energy, and momentum. The largest topic with fundamental formulas for understanding how objects move and interact.

Speed & Velocity Force Work Power Energy Moments

🌡️ Thermal Physics

Heat, temperature, and the behavior of gases. Understanding thermal energy transfer and gas properties.

Heat Capacity Latent Heat Gas Laws

🌊 Waves & Sound

Wave properties, sound, and light. Essential for understanding how energy travels through different media.

Wave Speed Light Sound

⚡ Electricity

Circuits, current, voltage, and resistance. The foundation for understanding all electronic devices.

Ohm’s Law Power Resistance

🧲 Magnetism

Magnetic fields and electromagnetic effects. Key to understanding motors, generators, and transformers.

Force on Wire Induction Solenoids

☢️ Atomic Physics

Radioactivity and nuclear physics. Understanding the structure of atoms and nuclear energy.

Half-life Decay

⚙️ Mechanics Formulas

Motion and Forces

Average Speed

\[ v = \frac{s}{t} \]

\[ v = \frac{d}{t} \]

v = speed (m/s)
s or d = distance (m)
t = time (s)

m/s

Think: “Very Small distance divided by Tiny time”

Average Velocity

\[ v = \frac{\Delta s}{\Delta t} \]

v = (final position – initial position) / time

v = velocity (m/s)
Δs = change in displacement (m)
Δt = change in time (s)

m/s

Velocity is a vector (has direction), speed is scalar (magnitude only).

Acceleration

\[ a = \frac{v – u}{t} \]

a = acceleration (m/s²)
v = final velocity (m/s)
u = initial velocity (m/s)
t = time (s)

m/s²

“A VUT aT” – formula for acceleration using velocities and time

Newton’s Second Law

\[ F = ma \]

F = force (N)
m = mass (kg)
a = acceleration (m/s²)

N (kg·m/s²)

The MOST important formula in mechanics!

Weight

\[ W = mg \]

W = weight (N)
m = mass (kg)
g = gravitational field strength (N/kg or m/s²)

On Earth, g ≈ 10 N/kg (or 9.8 m/s²)

Momentum

\[ p = mv \]

p = momentum (kg·m/s)
m = mass (kg)
v = velocity (m/s)

kg·m/s

“Mass times velocity gives powerful momentum”

Energy and Work

Work Done

\[ W = F \times d \]

W = work done (J)
F = force (N)
d = distance (m)

J (N·m)

Work is only done when force causes movement in the direction of the force.

Gravitational Potential Energy

\[ PE = mgh \]

PE = potential energy (J)
m = mass (kg)
g = gravitational field strength (N/kg)
h = height (m)

Kinetic Energy

\[ KE = \frac{1}{2}mv^2 \]

KE = kinetic energy (J)
m = mass (kg)
v = velocity (m/s)

Power

\[ P = \frac{W}{t} \]

\[ P = Fv \]

P = power (W)
W = work done (J)
t = time (s)
F = force (N)
v = velocity (m/s)

W (J/s)

Efficiency

\[ \text{Efficiency} = \frac{\text{Useful Energy Output}}{\text{Total Energy Input}} \times 100\% \]

\[ \eta = \frac{E_{out}}{E_{in}} \times 100\% \]

Efficiency can NEVER exceed 100% (conservation of energy)

Moment of a Force

\[ M = F \times d \]

M = moment (N·m)
F = force (N)
d = perpendicular distance from pivot (m)

N·m

Pressure and Density

Density

\[ \rho = \frac{m}{V} \]

ρ = density (kg/m³)
m = mass (kg)
V = volume (m³)

kg/m³

Pressure (Force/Area)

\[ P = \frac{F}{A} \]

P = pressure (Pa or N/m²)
F = force (N)
A = area (m²)

Pa (N/m²)

Pressure in Liquids

\[ P = \rho gh \]

P = pressure at depth (Pa)
ρ = density of liquid (kg/m³)
g = gravitational field strength (N/kg)
h = depth (m)

🌡️ Thermal Physics Formulas

Heat Energy (Temperature Change)

\[ Q = mc\Delta\theta \]

Q = heat energy (J)
m = mass (kg)
c = specific heat capacity (J/kg·°C)
Δθ = temperature change (°C or K)

Water: c = 4200 J/kg·°C

Latent Heat

\[ Q = mL \]

Q = heat energy (J)
m = mass (kg)
L = specific latent heat (J/kg)

During phase change, temperature stays constant!

Pressure Law (Gay-Lussac’s Law)

\[ \frac{P_1}{T_1} = \frac{P_2}{T_2} \]

(Temperature in Kelvin!)

P = pressure (Pa)
T = temperature (K)

Pa/K

T must always be in Kelvin (K), not °C!

Charles’ Law

\[ \frac{V_1}{T_1} = \frac{V_2}{T_2} \]

(Temperature in Kelvin!)

V = volume (m³)
T = temperature (K)

m³/K

Ideal Gas Law

\[ PV = nRT \]

P = pressure (Pa)
V = volume (m³)
n = number of moles
R = gas constant (8.31 J/mol·K)
T = temperature (K)

Pa·m³

🌊 Waves and Sound Formulas

Wave Speed

\[ v = f \lambda \]

v = wave speed (m/s)
f = frequency (Hz)
λ = wavelength (m)

m/s

“Velocity equals frequency times lambda” – the fundamental wave equation!

Frequency and Period

\[ f = \frac{1}{T} \]

f = frequency (Hz or s⁻¹)
T = period (s)

Snell’s Law (Refraction)

\[ n_1 \sin\theta_1 = n_2 \sin\theta_2 \]

n = refractive index
θ = angle (measured from normal)

dimensionless

Refractive Index

\[ n = \frac{\sin i}{\sin r} = \frac{c}{v} \]

i = angle of incidence
r = angle of refraction
c = speed of light in vacuum
v = speed of light in medium

dimensionless

Lens Formula

\[ \frac{1}{f} = \frac{1}{u} + \frac{1}{v} \]

f = focal length (m)
u = object distance (m)
v = image distance (m)

m⁻¹

Magnification

\[ m = \frac{h_i}{h_o} = \frac{v}{u} \]

m = magnification
h_i = image height
h_o = object height

dimensionless

m > 1: magnified, m < 1: diminished, m < 0: inverted

⚡ Electricity Formulas

Current, Voltage, and Resistance

Current

\[ I = \frac{Q}{t} \]

I = current (A)
Q = charge (C)
t = time (s)

A (C/s)

Voltage (Potential Difference)

\[ V = \frac{W}{Q} \]

V = voltage (V)
W = work/energy (J)
Q = charge (C)

V (J/C)

Ohm’s Law

\[ V = IR \]

V = voltage (V)
I = current (A)
R = resistance (Ω)

V (Ω·A)

The holy trinity of electricity: V = IR, I = V/R, R = V/I

Resistors in Series

\[ R_{total} = R_1 + R_2 + R_3 + \dots \]

R_total = total resistance (Ω)
R₁, R₂… = individual resistors (Ω)

Total resistance is always GREATER than any individual resistor

Resistors in Parallel

\[ \frac{1}{R_{total}} = \frac{1}{R_1} + \frac{1}{R_2} + \frac{1}{R_3} + \dots \]

R_total = total resistance (Ω)

Total resistance is always LESS than the smallest resistor

Electrical Power and Energy

Electrical Power

\[ P = VI \]

also:

\[ P = I^2R \]

\[ P = \frac{V^2}{R} \]

P = power (W)
V = voltage (V)
I = current (A)
R = resistance (Ω)

All three are equivalent – use the one that fits your known values!

Electrical Energy

\[ E = Pt \]

\[ E = VIt \]

E = energy (J or kWh)
P = power (W)
t = time (s or h)

J or kWh

1 kWh = 3.6 × 10⁶ J

EMF and Internal Resistance

\[ E = V + Ir \]

E = I(R + r)

E = EMF (V)
V = terminal voltage (V)
I = current (A)
R = external resistance (Ω)
r = internal resistance (Ω)

🧲 Magnetism and Electromagnetism Formulas

Force on Current-Carrying Wire

\[ F = BIL \sin\theta \]

F = force (N)
B = magnetic field strength (T)
I = current (A)
L = length of wire (m)
θ = angle between wire and field

Maximum force when wire is perpendicular to field (θ = 90°)

Fleming’s Left-Hand Rule

Thumb = Force (motion)

First finger = Field (N to S)

Second finger = Current (+ to -)

“FBI” – From B to I gives Force!

Magnetic Flux

\[ \Phi = BA \cos\theta \]

Φ = magnetic flux (Wb)
B = magnetic field (T)
A = area (m²)
θ = angle to normal

Wb (T·m²)

Faraday’s Law (EMF)

\[ \varepsilon = -N \frac{\Delta\Phi}{\Delta t} \]

ε = induced EMF (V)
N = number of turns
ΔΦ/Δt = rate of change of flux (Wb/s)

Negative sign indicates Lenz’s Law (opposes the change)

Magnetic Field of Solenoid

\[ B = \mu_0 n I \]

B = magnetic field (T)
μ₀ = 4π × 10⁻⁷ T·m/A
n = turns per meter (m⁻¹)
I = current (A)

Transformer Equation

\[ \frac{V_p}{V_s} = \frac{N_p}{N_s} \]

V = voltage (V)
N = number of turns
p = primary, s = secondary

dimensionless

“Vampire Necks” – V and N are directly proportional

☢️ Atomic Physics Formulas

Half-Life

\[ N = N_0 \left(\frac{1}{2}\right)^n \]

or: \( N = N_0 e^{-\lambda t} \)

N = remaining amount
N₀ = initial amount
n = number of half-lives
t = time elapsed
T½ = half-life

various

n = t / T½

Activity

\[ A = \lambda N \]

A = activity (Bq)
λ = decay constant (s⁻¹)
N = number of atoms

Bq (decays/s)

🔢 Important Constants

Constant	Symbol	Value	Unit
Gravitational field strength	g	10 (or 9.8)	N/kg or m/s²
Speed of light in vacuum	c	3.0 × 10⁸	m/s
Speed of sound (air)	v	340	m/s
Specific heat capacity of water	c	4200	J/kg·°C
Permeability of free space	μ₀	4π × 10⁻⁷	T·m/A
Gas constant	R	8.31	J/mol·K
Charge on electron	e	1.6 × 10⁻¹⁹	C
Mass of electron	mₑ	9.11 × 10⁻³¹	kg
Mass of proton	mₚ	1.67 × 10⁻²⁷	kg

📐 Unit Conversions

Length

↔

1 km = 1000 m
1 m = 100 cm = 1000 mm

Mass

↔

1 tonne = 1000 kg
1 kg = 1000 g

Time

↔

1 hour = 3600 s
1 minute = 60 s

Temperature

↔

°C + 273 = K
K – 273 = °C

Energy

↔

1 kWh = 3.6 × 10⁶ J
1 Cal = 4.2 J

Pressure

↔

1 atm = 101325 Pa
1 bar = 10⁵ Pa

🎯 Formula Success Tips

📝

Examination Strategy

Write down the formula first – Even if you can’t remember it exactly, writing what you know shows working and may earn partial credit.
Check units – Always ensure your units are consistent (convert everything to SI units before calculating).
Identify what’s given vs. what’s asked – Underline the known values and box what you need to find.
Rearrange before substituting – It’s easier to solve algebraically first, then plug in numbers.
Check for reasonableness – Does your answer make sense? (A car won’t travel at 1,000,000 m/s!)

🔤 Common Memory Tricks

Ohm’s Law: “VIR” triangle – cover what you need, remaining gives formula
F = ma: “F = ma, ma, ma” (force is massive!)
v = fλ: “Very Fast Lambdas” – velocity is frequency times wavelength
KE = ½mv²: “Half my velocity squared gives kinetic energy”
FBI: Fleming’s Left Hand = Field, Current, Force (From B to I = Force)

⚠️ Common Mistakes to Avoid

Using mass instead of weight (or vice versa)
Confusing speed with velocity (vector vs scalar)
Forgetting to convert temperature to Kelvin for gas laws
Using cm² instead of m² for area
Mixing up parallel and series resistor formulas
Using diameter instead of radius in circular motion
Forgetting the angle in F = BILsinθ

📋 Mastery Checklist

Can you…

Calculate speed, velocity, and acceleration?

Apply Newton’s laws to solve force problems?

Calculate work, energy, and power?

Use the principle of moments?

Calculate pressure in solids and liquids?

Apply heat capacity and latent heat formulas?

Can you…

Use wave equation v = fλ?

Apply Snell’s law and lens formula?

Use Ohm’s law and calculate power?

Combine resistors in series and parallel?

Apply F = BIL and Fleming’s Left-Hand Rule?

Calculate induced EMF using Faraday’s Law?