Physics is about understanding concepts and applying formulas. This guide will help you master both for your GCE exams.
1. Memorize Essential Formulas
These formulas appear in almost every Physics exam:
Motion
v = u + at
s = ut + ½at²
v² = u² + 2as
Forces
F = ma
W = mg
P = F/A
Energy
KE = ½mv²
PE = mgh
W = Fd
Electricity
V = IR
P = IV
E = Pt
Waves
v = fλ
T = 1/f
Pressure
P = ρgh
P = F/A
Formula Tip: Don't just memorize - understand what each variable means and when to use each formula.
2. Know Your Units
Always include units in your answers. Common units:
- Force: Newtons (N)
- Energy/Work: Joules (J)
- Power: Watts (W)
- Velocity: m/s
- Acceleration: m/s²
- Pressure: Pascals (Pa) or N/m²
- Resistance: Ohms (Ω)
- Current: Amperes (A)
- Voltage: Volts (V)
3. Master Graph Interpretation
Physics exams love graphs. Know how to interpret:
Distance-Time Graphs
- Gradient = velocity
- Horizontal line = stationary (not moving)
- Steeper slope = faster speed
Velocity-Time Graphs
- Gradient = acceleration
- Area under graph = distance traveled
- Horizontal line = constant velocity (zero acceleration)
- Below x-axis = moving backwards
4. Electricity Topics
Electricity questions are very common. Master these:
Circuit Calculations
Series: R_total = R₁ + R₂ + R₃
Parallel: 1/R_total = 1/R₁ + 1/R₂ + 1/R₃
Parallel: 1/R_total = 1/R₁ + 1/R₂ + 1/R₃
Key Concepts
- In series: Current same everywhere, voltage splits
- In parallel: Voltage same across all branches, current splits
- Ammeter: Connected in series, measures current
- Voltmeter: Connected in parallel, measures voltage
5. Vectors and Forces
You must be able to:
- Draw free body diagrams
- Resolve forces into components (using sin and cos)
- Find resultant forces
- Understand equilibrium (forces balance)
6. Problem-Solving Steps
- Read carefully - underline key information
- List what you know - write down given values with units
- Identify what you need - what variable are you finding?
- Choose the formula - which equation has these variables?
- Substitute and solve - plug in numbers, calculate
- Check units - does your answer have correct units?
Show Your Working: Even if your final answer is wrong, you can get marks for correct method. Always show each step!
7. Common Mistakes
- Forgetting to convert units (km → m, minutes → seconds)
- Using wrong formula for the situation
- Not showing working (you lose method marks)
- Confusing mass and weight
- Forgetting negative signs for direction
Practice: Physics requires lots of problem practice. Work through O Level Physics papers and A Level Physics papers.