Real Oxford and Cambridge Physics interview problems, worked through as reasoning rather than as answers — the single point between the Earth and the Moon where gravity cancels completely, and why a bungee rope's safe length turns on the gap between its elastic modulus and the jumper's own weight, not the modulus alone.
An Oxbridge Physics interviewer rarely accepts a formula on its own; you're expected to derive it live and defend every step once an assumption changes. The Dynamics and Fields pack drills exactly that discipline through gravitational-field problems — orbits, a cancellation point between two masses, energy-conservation setups — each one reasoned out in full rather than compressed into a final answer, so you can see precisely where the working actually gets hard.
The Dynamics and Fields pack — £180
Ten questions across 26 pages. Each is set down three ways: the bare question, the hints to lean on once you stall, then a complete worked answer. One PDF, one payment, instant download.
Get the Dynamics and Fields pack — £180Read the free sample firstStraight to payment — no account, instant download.
Oxford and Cambridge Physics interviews are problem-solving sessions that resemble the opening minutes of a research conversation. Interviewers present physical scenarios — some familiar in structure, all unfamiliar in specific detail — and ask you to reason your way to an answer while they observe. The process is the assessment. A candidate who reaches the correct answer silently is less impressive than one who demonstrates rigorous physical thinking, clear communication, and the ability to self-correct under pressure. That is an awkward thing to rehearse alone, because the part being marked is the part you normally do silently in your head. The way round it is to work through problems whose solutions are set out as reasoning rather than as answers, so you can lay your own line of thought against a physicist’s and see where the two part company — which is what the Dynamics and Fields pack is built to let you do. Below: the four question types with three of them answered in full, a worked estimation with its arithmetic shown, and a straight account of what is in the free sample, so you can judge the material before you decide anything.
Oxford Physics candidates typically have two 25–30 minute panel interviews at their applied college. One interview often focuses on mechanics, electromagnetism, and mathematical physics; the other on waves, thermodynamics, or modern physics — though this varies by college. Cambridge Natural Sciences (Physical) candidates have two panel interviews reflecting the broad first-year NatSci syllabus. Oxford Physics uses the ESAT for shortlisting from 2027 entry, having replaced the PAT after its final sitting in autumn 2025. Cambridge NatSci has used the ESAT since 2025. Approximately 190 students are admitted to Oxford Physics annually. A panel interview is not a viva, and nothing is being checked off a syllabus. The problem is chosen precisely because you cannot have prepared it, which is why the opening thirty seconds carry more weight than the last five minutes: a candidate who starts by writing down what is known and naming an assumption out loud has already given the interviewer something to work with, while a candidate who goes quiet has given them nothing to assess at all.
| Factor | Oxford Physics | Cambridge NatSci (Physical) |
|---|---|---|
| Annual intake | ~190 | ~250+ (Physical route) |
| Pre-interview test | ESAT from 2027 (PAT until 2026) | ESAT from 2025 |
| Interview format | 2 panel interviews | 2 panel interviews; pool possible |
| Estimation questions | Very common | Common |
| Mathematics required | Calculus, vectors, dimensional analysis | Calculus, vectors, formal maths |
Gravitational fields and orbital mechanics. Several questions build directly on Newton's law of gravity and ask you to reason about where its effects cancel, where they balance, or how they combine into an orbit. One gives the Earth a radius four times the Moon's and asks you to find the single point between them where a particle would feel no net gravitational pull at all, then to show — by reasoning about gravitational potential rather than force — whether that point is a stable or an unstable equilibrium. A related question pushes further: describe every point in space, not just the one between the bodies, where the two pulls are equal in magnitude. The algebra along the way briefly looks like the equation for a circle; only after completing the square does it resolve into what the question is really asking for — the equation of a sphere. A third drills a hole through the centre of a uniform-density Earth and drops a coin in — only the mass inside the coin's own distance from the centre pulls on it, and that single fact is enough to show the coin executes simple harmonic motion rather than falling straight through and stopping. A fourth uses Kepler's third law to find the orbital radius that matches Earth's rotation, then energy conservation between the launch point and that orbit to find the minimum initial speed needed to reach it.
Energy conservation for escape and closest-approach problems. Two further questions apply the same method — set the kinetic energy you start with against the work done against a field — to very different systems. One derives Earth's escape velocity from scratch: integrate the gravitational force from the surface to infinity, equate that to the kinetic energy of a departing rocket, and solve for the minimum launch speed, before a follow-up asks how the answer would change once air resistance, a fuel-burning rocket's changing mass, and other real complications are allowed back in. The other fires an alpha particle at half the speed of light directly at a lead-207 nucleus and asks for its distance of closest approach, which falls out of exactly the same energy method once the gravitational potential is swapped for the electrostatic one between two charges — the pack's one deliberately cross-disciplinary question, dynamics wearing an atomic-physics coat. The harder part of the answer is arguing that firing an alpha particle at half the speed of light is itself an unrealistic premise, since real alpha decay is far slower.
Elastic energy and a realistic projectile twist. A bungee-jump question turns a genuine design problem into elastic-potential-energy calculus: given a valley 150 metres deep and a rope of unknown modulus of elasticity, integrate the elastic force from the rope's natural length to find the longest rope a jumper of a given mass could safely use, so that gravitational and elastic potential energy balance exactly at the bottom of the fall. A companion question takes the textbook ‘monkey hunter’ projectile problem and adds a realistic complication: the monkey does not fall the instant the gun fires, only once the sound of the shot reaches it, and working out how far it falls in that short delay — then where the hunter should actually aim, at a small angle above the horizontal found using the small-angle approximation — is the whole of the answer.
Momentum conservation and forces that vary with position. A two-particle collision question is solved the harder, more general way: rather than reaching for a coefficient of restitution, you write down the two simultaneous equations for conserved momentum and conserved kinetic energy and solve them together — for a heavier particle starting at twice the speed u of the lighter one, the algebra resolves to final speeds of 1.5u for the heavier particle and 2.5u for the lighter one, arithmetic an interviewer expects you to finish, not wave at. Two more questions ask you to reason qualitatively about a force that changes as an object moves through it, without ever finishing a calculation: sketching how a metal ball's velocity and acceleration change as it falls from the upper atmosphere through steadily denser air, and reasoning through the symmetry of a pinball moving down the axis of a hollow, ring-shaped mass (a toroid), where the pull of gravity reverses direction exactly at the centre.
Two questions taken all the way here: the Earth-Moon point where gravity cancels, and a collision solved by simultaneous equations rather than a shortcut formula.
Dynamics and Fields is the Physics pack — £180, one payment, downloadable straight afterwards. It is the complete set of ten questions across gravitational fields and orbits, energy conservation for escape and closest-approach problems, elastic energy and a realistic projectile twist, and momentum conservation and varying-force reasoning, each with a full model answer. Do not take that on trust: read the free sample first — two complete questions from a different, standalone pair (an hourglass and a dice-rolling puzzle), with their hints and solutions, eight pages, a direct PDF download with no account required.
Eight pages, two questions, three parts each, in three layers you read in order. First the questions on their own: a running hourglass stood on a high-resolution balance, and a handful of six-sided dice from which every six is removed on each roll. Then one hints page you turn to only when stuck, which for the hourglass offers three single lines — break the problem into three phases; think about the sand that has left the top but not yet landed; consider the collision when it does — and nothing further. Then six pages of worked solution: the hourglass argued out in bullets rather than in lines of algebra, the dice worked through as algebra in full. The hourglass answer reasons separately about sand in free fall, sand landing on the base, and the brief maximum in the reading just as the last grains leave the top, then sketches the graph that follows. The dice answer forms a first-order differential equation, solves it with an integrating factor to N = ne−t/6, argues that you should solve for N = ½ rather than N = 0 because the curve never actually reaches zero, and only then points out that the same equation is radioactive decay with a decay constant of one sixth. At one point the solution stops to call an assumption it has just made ‘a rather poor assumption’ — flagging your own weak step before anyone else does is the habit being taught, and it is the habit interviewers are listening for.
Estimation questions are structured reasoning exercises, not guessing games. Start by identifying the relevant physical relationship or formula. Then estimate each required parameter with a stated justification: "Air density is approximately 1.2 kg/m³." "A cyclist's frontal area is roughly 0.5 m²." Combine the estimates using the physical relationship and state the result with appropriate significant figures. Then sanity-check: "This implies a power requirement of about 600 W at that speed, which seems slightly high but the right order of magnitude — a professional cyclist produces 200–400 W, so the discrepancy is within the expected accuracy of this calculation." Narrating this check aloud signals mature physical thinking. Written out in full, a drag estimate runs like this. Drag goes as F = ½ρCdAv², so three things need estimating: the density of air, the product of drag coefficient and frontal area, and the speed in SI units. Thirty miles per hour is a shade over 13 m/s, so v² is about 180 m²/s². Take ρ as 1.2 kg/m³, and a frontal area of 0.5 m² with a drag coefficient near 0.8, so CdA is roughly 0.4 m². That gives F ≈ 0.5 × 1.2 × 0.4 × 180 ≈ 43 N, and the power needed to overcome it is Fv ≈ 43 × 13.4 ≈ 580 W. Every input there is soft to within a factor of two, and saying so is part of the answer: the claim being made is that the power is hundreds of watts rather than tens or thousands, and the professional’s 200–400 W is what tests that claim. If the interviewer then doubles the speed, they are checking whether you know the power scales as v³ and not as v — which is the physics the whole estimate was really about.
"I had no idea what to expect from my interview at Magdalen — A-level gives you no preparation for the style of question they ask. Working through the pack beforehand meant I'd practised thinking through problems I'd never seen before and talking through my reasoning out loud. When I got stuck in the actual interview, I knew how to keep going rather than freeze. I got my offer in January."— James H., Mathematics, Magdalen College Oxford, 2024 entry
“My panel at Gonville & Caius handed me a short article about a clinical trial and asked what I thought the key limitation was. I’d never seen the paper before. The pack was the only preparation I found that actually trains you for that — reading through the model answers showed me how to reason about evidence out loud, identifying what is missing or uncertain rather than just summarising what is there. By the time I got into the room I knew how to think, not just what to say.”— Priya S., Medicine, Gonville & Caius Cambridge, 2024 entry
The pack's ten questions fall into four repeating shapes: gravitational-field problems about where a force cancels, where it is equal in magnitude between two bodies, or how an orbit is reached; energy-conservation problems applied to escape velocity and to an alpha particle's closest approach to a nucleus; a bungee-rope design problem and a projectile problem with a built-in sound-delay twist; and momentum-conservation and varying-force problems, including gravity through a hollowed-out Earth and around a toroid. Oxford and Cambridge Physics interviews more broadly also range into electromagnetism, waves and Fermi estimation — none of which this particular pack covers.
Fermi estimation questions ask you to estimate a physical quantity from first principles without precise data. Examples: 'How many piano tuners are in London?' 'Estimate the drag force on a cyclist at 30 mph.' The correct approach: identify the relevant physical relationship or formula, estimate each required parameter with a stated justification, combine the estimates using the physics, and sanity-check the result. The process — systematic parameter identification and explicit reasoning — matters more than arriving at the precise correct number. Practise narrating every step aloud, including the sanity check.
Oxford Physics uses the ESAT for shortlisting from 2027 entry, having replaced the PAT (Physics Admissions Test) after its final sitting in autumn 2025. Cambridge NatSci has used the ESAT since 2025. The ESAT covers physics and mathematics at A-level and beyond. A strong score significantly improves your shortlisting position. Once you reach the interview, the test score plays little direct role — the interview conversation determines the offer. Always check the official admissions pages for the test requirements specific to your entry year, as these are changing for several subjects.
Mathematics is central. Expect to use calculus (differentiation and integration in mechanics and electromagnetism), vectors (field descriptions, force resolution), differential equations (oscillating systems, circuit transients), and dimensional analysis (verifying the form of physical relationships). The emphasis is on setting up equations correctly and reasoning about solutions qualitatively — not on fast numerical computation. A candidate who correctly sets up the differential equation for an RL circuit and explains its qualitative solution will score better than one who quotes the time constant formula without derivation.
Both use two panel interviews of 25–30 minutes. Oxford Physics interviews often divide by topic — one focused on mechanics and electromagnetism, another on waves, thermodynamics, or modern physics — though this varies by college. Cambridge NatSci (Physical) interviews reflect the first-year breadth, potentially combining physics with chemistry and mathematics in a single problem. The main practical difference is the admissions test: Oxford used the PAT until 2026 entry; Cambridge has used the ESAT since 2025. From 2027 entry both use the ESAT.
This page names the pack's four question shapes and narrates three of them in full, free — the Earth-Moon equilibrium point, the escape-velocity derivation, and the two-particle collision solved by simultaneous equations. Dynamics and Fields is the complete set behind them: ten questions across gravitational fields and orbits, energy conservation for escape and closest-approach problems, elastic energy and a realistic projectile twist, and momentum conservation and varying-force reasoning, each with a full worked answer, as a one-off £180 download you can print and work through at your own pace. The free eight-page sample is a separate, standalone question pair — an hourglass on a balance and a dice-rolling probability puzzle — included to show the level the answers are written at, not a preview cut from Dynamics and Fields itself.
Honestly, no — not on its own. A written model answer can show you everything about the content of a good answer: the assumptions you state, the relationship you set up, the sanity check you run at the end. What it cannot do is hear you. It will not tell you that you went quiet for forty seconds, it will not interrupt with 'but surely...' halfway through a derivation, and it will not notice that your reasoning was sound but nobody in the room could follow it. Work through the pack for the physics, then argue the solutions out loud to a physicist, a teacher, or a friend who will push back. The pack fixes the thinking; only a listener fixes the delivery.
Dynamics and Fields is £180 as a single one-off purchase, added from the resource hub, and access is immediate once payment goes through — there is nothing to book and nothing to wait for. A bundle discount is applied automatically at checkout: 10% off two packs, 20% off three or more. That is worth knowing if you are applying for Cambridge Natural Sciences, where one interview problem can range across physics, chemistry and mathematics, and a second pack covers the half of that range Dynamics and Fields does not.
Further Reading: For Oxford Physics interview questions including estimation problems and worked solutions, see our companion guide: Oxford Physics Interview Questions 2026 — Estimation Problems and Worked Solutions.
Two questions with their full solutions, free. Then the rest of them.
The sample is eight pages and costs nothing to check, and it is a finished piece of work rather than a teaser — hints you can ignore, and solutions that stop to criticise their own assumptions. If those model answers read the way you want your own answers to sound, Dynamics and Fields is the complete set — £180, one payment, access straight after. Leading Tuition is rated Excellent on Trustpilot (4.8/5). That is the company’s rating, not a rating of this pack.