GCSE Physics Equation Sheet: Every Formula You Need to Know

GCSE Physics equations can feel overwhelming at first glance. Between forces, energy, electricity, waves, and radioactivity, there’s a lot to remember. The good news? Your exam board provides an equation sheet with many of the formulas you’ll need. The challenge is knowing which equations are given, which you must memorise, and how to use them all correctly under exam pressure.

What’s Actually on the GCSE Physics Equation Sheet?

The equation sheet you receive in your GCSE Physics exam contains about 20-25 key formulas, though this varies slightly by exam board (AQA, Edexcel, OCR). The sheet typically includes the more complex equations from topics like:

Forces and motion – equations involving acceleration, momentum, force
Energy – work done, kinetic energy, gravitational potential energy, power
Electricity – potential difference, resistance, electrical power
Waves – wave speed, frequency, wavelength
Atomic structure – radioactive decay equations

The equation sheet does NOT include simpler formulas like density = mass ÷ volume or speed = distance ÷ time. You’re expected to know these from memory.

Equations You MUST Memorise

Not everything appears on the equation sheet. You absolutely need to memorise these fundamental equations:

Forces:

weight = mass × gravitational field strength (W = mg)
speed = distance ÷ time (v = s/t)

Energy:

efficiency = useful energy output ÷ total energy input
charge flow = current × time (Q = It)

Electricity:

potential difference = current × resistance (V = IR)

Waves:

wave speed = frequency × wavelength (v = fλ)

These basic equations come up repeatedly across different question types. If you can’t recall them instantly, you’ll waste precious exam time.

Equations by Topic: What You Need to Know

Forces and Motion

Given on the sheet:

force = mass × acceleration (F = ma)
momentum = mass × velocity (p = mv)
kinetic energy = ½ × mass × velocity² (KE = ½mv²)

Must memorise:

weight = mass × gravitational field strength (W = mg)
work done = force × distance (W = Fs)

Common exam questions ask you to calculate acceleration from force and mass, or to work out momentum before and after collisions. Remember that acceleration and momentum are vector quantities – direction matters.

Energy

Given on the sheet:

gravitational potential energy = mass × gravitational field strength × height (GPE = mgh)
power = energy transferred ÷ time (P = E/t)
power = work done ÷ time (P = W/t)

Must memorise:

efficiency = useful energy output ÷ total energy input

Energy conservation problems often require you to equate gravitational potential energy at the top with kinetic energy at the bottom, accounting for efficiency losses. Show every step in your working.

Electricity

Given on the sheet:

power = potential difference × current (P = VI)
power = current² × resistance (P = I²R)
energy transferred = power × time (E = Pt)
energy transferred = charge flow × potential difference (E = QV)

Must memorise:

potential difference = current × resistance (V = IR) – Ohm’s Law
charge flow = current × time (Q = It)

Circuit questions test whether you understand series vs parallel circuits. Remember: in series, current is the same everywhere; in parallel, potential difference is the same across branches.

Waves

Given on the sheet:

wave speed = frequency × wavelength (v = fλ) – sometimes given, sometimes expected to know

Must memorise:

period = 1 ÷ frequency (T = 1/f)

Wave calculations are usually straightforward if you keep your units consistent. Frequency is in hertz (Hz), wavelength in metres (m), speed in metres per second (m/s).

Magnetism and Electromagnetism

Given on the sheet:

force on a conductor = magnetic flux density × current × length (F = BIL)
potential difference across primary coil ÷ potential difference across secondary coil = number of turns on primary ÷ number of turns on secondary (Vp/Vs = Np/Ns) – transformer equation

These appear less frequently but are worth significant marks when they do. Don’t skip magnetism revision.

Radioactivity

Given on the sheet:

activity = number of nuclei × decay constant (A = λN)
net decline = initial activity × e^(-λt) (radioactive decay equation)

These equations look complex, but exam questions guide you through them step-by-step. You won’t need to derive them from scratch.

How to Rearrange Equations Effectively

Many students lose marks not because they don’t know the equation, but because they can’t rearrange it. Here’s a systematic method:

Example: You know F = ma, but you need to find acceleration.

Write out the original equation: F = ma
Identify what you’re solving for: a
Isolate it by dividing both sides by m: a = F/m

Triangle method:

For equations with three variables like V = IR, draw a triangle:

    V
   ---
   I R

Cover what you’re solving for:

Want V? V = I × R
Want I? I = V ÷ R
Want R? R = V ÷ I

This works for any equation with three variables (speed = distance ÷ time, density = mass ÷ volume, etc.).

Common Mistakes with GCSE Physics Equations

1. Forgetting to convert units

If mass is in grams, convert to kilograms. If distance is in centimetres, convert to metres. Exam questions deliberately use different units to test your attention to detail.

2. Not showing working

Even if you get the final answer wrong, you can still earn method marks. Write down the equation, substitute values, then calculate. Never just write a final number.

3. Mixing up similar equations

Students often confuse:

Weight (W = mg) with work done (W = Fs)
Kinetic energy (KE = ½mv²) with gravitational potential energy (GPE = mgh)
The two power equations (P = E/t and P = VI)

Read questions carefully. Look for keywords: “lifted” or “height” suggests GPE; “moving” or “velocity” suggests kinetic energy.

4. Ignoring significant figures

Your answer should have the same number of significant figures as the data given in the question, usually 2 or 3. Check the mark scheme – marks are lost for incorrect significant figures.

5. Getting the direction wrong

Force, velocity, acceleration, and momentum all have direction. If an object moves left then right, the velocity changes direction, which affects calculations involving momentum or energy.

Worked Examples from Past Papers

Example 1: Forces and Motion

A car of mass 1,200 kg accelerates from rest to 15 m/s in 8 seconds. Calculate the force required.

Step 1: Calculate acceleration using a = (v - u) / t = (15 - 0) / 8 = 1.875 m/s² Step 2: Use F = ma = 1,200 × 1.875 = 2,250 N

Example 2: Energy

A 60 kg student climbs stairs to a height of 3 m. Calculate the gravitational potential energy gained. (g = 10 N/kg)

Step 1: Use GPE = mgh = 60 × 10 × 3 = 1,800 J

Example 3: Electricity

A 6 V battery pushes 2 A of current through a resistor. Calculate the resistance.

Step 1: Use V = IR, rearrange to R = V / I = 6 / 2 = 3 Ω

How UpGrades Helps with Physics Equations

Knowing equations isn’t enough – you need to recognise when to use each one and apply them accurately under exam conditions. UpGrades provides targeted practice questions that test your ability to:

Select the correct equation for each scenario
Rearrange equations to solve for different variables
Convert units correctly
Interpret complex multi-step problems

With instant feedback on every answer, you’ll quickly identify which equations you’re comfortable with and which need more practice. The adaptive system ensures you spend time where it matters most – strengthening your weak areas before exam day.

Final Tips for GCSE Physics Equations Success

1. Create a formula sheet for memorisation

Write out the equations you must memorise (the ones NOT on the equation sheet) on a single page. Test yourself daily until you can recall them all instantly.

2. Practise applying equations, not just memorising them

Do past paper questions that require multiple steps. Real exam questions rarely give you all the values directly – you might need to calculate something first before using it in another equation.

3. Learn the units

Force is in newtons (N), energy in joules (J), power in watts (W), resistance in ohms (Ω). Knowing units helps you check if your answer makes sense.

4. Use the equation sheet in timed conditions

Practise finding equations on the sheet quickly. In the actual exam, you don’t want to waste 2 minutes searching for the momentum equation.

5. Check your calculator

Make sure you know how to enter calculations correctly. Use brackets for fractions and squares. A simple calculator error can cost you marks even when your method is perfect.

GCSE Physics equations are manageable once you understand which ones you need to memorise, how to rearrange them, and when to apply each one. Combine this knowledge with regular practice using past papers and UpGrades’ adaptive question practice, and you’ll approach your physics exam with confidence.