The 2007 paper is the earliest year in this archive, with a plain, solid style: direct use of core formulas and short two- or three-step chains dominate, and the density of basic mechanics and electromagnetism questions is high. Ideal for building fundamentals. Scan the QR code for the past paper and answers.
The 25 online practice questions start instantly; the full past-paper & answers PDF is available free from an advisor via the QR code — it is not a direct download on this page.2007 Physics Bowl paper overview and exam highlights.
The 2007 Physics Bowl kept its classic format: 40 multiple-choice questions in 45 minutes, an all-English paper, calculators allowed, points for correct answers and no penalty for wrong ones. Division 1 serves first-year students and beginners, with no calculus on the paper; Division 2 serves second-year and AP Physics C students. The two divisions are ranked and awarded separately, and entering both is not allowed. The contest is held in spring each year (around late March to early April), with registration deadlines per the official announcement.
As the earliest year in this archive, the 2007 paper shows the classic face of early Physics Bowl: direct and combined use of core formulas with few oddball problems. Mechanics spans kinematics, Newton laws, momentum and energy, gravitation and simple harmonic motion; electromagnetism takes a visible share with circuit analysis, induction, capacitance and charged particles in magnetic fields spread evenly; thermodynamics centers on specific heat and the first law; waves and optics are represented by refractive index and interference fringe calculations; modern physics brings half-life, mass-energy and length contraction. Numbers stay tidy throughout, making this paper a good test of solid fundamentals.
If you plan to work through the Physics Bowl in chronological order, starting with 2007 is the natural choice. Scan the QR code to add our consultant on WeChat and receive the 2007 past paper, answers and full explanations, then treat the 25 original questions on this page as a placement-style self-test.
2007 Physics Bowl main topic areas, weights and emphasis.
A high density of direct questions, with kinematics and short force chains covering nearly forty percent.
A visible share: circuits, induction, capacitance and magnetic-field problems spread evenly.
Refractive index and fringe calculations lead, with occasional wave concept questions.
Specific heat and the first law are the main scoring points, generally at low difficulty.
Half-life, mass-energy and length contraction appear steadily as concept questions.
2007 Physics Bowl-style mock questions (Basic · Medium · Hard) — submit to grade and view step-by-step solutions.
A sled glides across ice at 12 m/s and slows steadily to a stop in 4 s. What is the magnitude of its acceleration?
Correct answer: B
a = Δv/Δt = 12/4 = 3 m/s2; 0.33 uses Δt/Δv. Core: a = Δv/Δt, opposite in direction to the motion when slowing.A stone is dropped from rest into a well, and the splash is heard 5 s later (ignore the travel time of sound, g = 10 m/s2). How deep is the water surface below the rim?
Correct answer: D
h = ½gt2 = ½ × 10 × 25 = 125 m; 250 m omits the ½. Core: h = ½gt2.The Moon has a mass of about 7.3×1022 kg and a radius of about 1.7×106 m, with G = 6.7×10-11 N·m2/kg2. What is the gravitational acceleration at the surface of the Moon?
Correct answer: C
g = GM/R2 = 6.7×10-11 × 7.3×1022 / (1.7×106)2 ≈ 1.7 m/s2; 0.17 m/s2 is an order-of-magnitude slip. Core: surface gravity g = GM/R2.A ball of mass 0.5 kg rolls at 8 m/s. What is its kinetic energy?
Correct answer: E
KE = ½mv2 = ½ × 0.5 × 64 = 16 J; 64 J omits the ½ factor. Core: kinetic energy = ½mv2.A kettle heating element has a resistance of 20 Ω and carries a working current of 5 A. What is the voltage across the element?
Correct answer: B
V = IR = 20 × 5 = 100 V; 4 V uses R/I. Core: V = IR.A 12 Ω and a 6 Ω resistor are connected in parallel. What is the equivalent resistance?
Correct answer: A
R = (12×6)/(12+6) = 72/18 = 4 Ω; 18 Ω adds them as if in series, and 9 Ω takes the average. Core: a parallel combination is smaller than either resistor.A 20 μF capacitor is charged to 9 V. How much charge does it store?
Correct answer: D
Q = CU = 20 μF × 9 V = 180 μC; 2.2 μC uses U/C. Core: Q = CU.A tuning fork vibrates at a frequency of 250 Hz. What is its period of oscillation?
Correct answer: C
T = 1/f = 1/250 = 0.004 s; 0.25 s comes from mishandling the reciprocal. Core: T = 1/f.A 0.5 kg metal block absorbs 3000 J of heat and warms by 20 ℃. What is the specific heat of the metal?
Correct answer: A
From Q = mcΔT, c = Q/(mΔT) = 3000/(0.5 × 20) = 300 J/(kg·℃); 150 skips the mass. Core: specific heat c = Q/(mΔT).In a nuclear reaction, 1×10-16 kg of mass is converted into released energy (c = 3×108 m/s). How much energy is released?
Correct answer: B
E = mc2 = 1×10-16 × (3×108)2 = 9 J. Core: E = mc2.A ball is thrown at 20 m/s, 30° above the horizontal (g = 10 m/s2). How long is it in the air?
Correct answer: C
The vertical component is vy = 20 × sin30° = 10 m/s, so the total time is t = 2vy/g = 2 × 10/10 = 2 s; 1 s omits the factor of 2. Core: total flight time = 2 × vertical launch component / g.A 50 kg passenger stands in an elevator accelerating upward at 2 m/s2 (g = 10 m/s2). What does the scale read?
Correct answer: E
Accelerating up: N − mg = ma, so N = m(g + a) = 50 × 12 = 600 N; 400 N applies the deceleration formula m(g − a). Core: apparent weight = m(g + a) when accelerating upward.Two satellites orbit the same planet in circular orbits, with satellite B at 9 times the orbital radius of satellite A. How many times longer is the period of B?
Correct answer: D
Kepler third law gives T2 ∝ r3, so 9 times the radius means √(93) = √729 = 27 times the period; 9 uses a linear relation. Core: T ∝ r3/2.An object moves along the x axis in simple harmonic motion with frequency 2 Hz and amplitude 0.05 m. What is its maximum speed as it passes through equilibrium (π = 3.14)?
Correct answer: B
vmax = 2πfA = 2 × 3.14 × 2 × 0.05 = 0.628 ≈ 0.63 m/s; 0.2 m/s omits π. Core: maximum speed in SHM is 2πfA.A circuit places a 12 Ω and a 6 Ω resistor in parallel, in series with a 4 Ω resistor, across a 24 V battery. What is the voltage across the parallel pair?
Correct answer: A
The parallel pair gives 4 Ω, the total is 8 Ω, the current is I = 24/8 = 3 A, and the parallel voltage is 3 × 4 = 12 V; 24 V assigns the source voltage directly. Core: find the total resistance and current first, then the local voltage.An electron of charge 1.6×10-19 C and mass 9.1×10-31 kg moves at 3×106 m/s perpendicular to a uniform 0.002 T magnetic field. What is the radius of its circular path?
Correct answer: E
r = mv/(qB) = 9.1×10-31 × 3×106 / (1.6×10-19 × 0.002) ≈ 8.5×10-3 m = 8.5 mm. Core: the radius of a charged particle circling in a field is r = mv/(qB).Monochromatic light of wavelength 600 nm in vacuum enters a medium where its wavelength becomes 450 nm. What is the refractive index of the medium?
Correct answer: B
The frequency is unchanged, so wavelength and speed shrink by the same factor: n = λvacuum/λmedium = 600/450 ≈ 1.33; 0.75 inverts the ratio. Core: n = vacuum wavelength / medium wavelength.In a double-slit experiment, the slits are 0.1 mm apart, the screen is 2 m away, and adjacent bright fringes are measured 12 mm apart. What is the wavelength of the light?
Correct answer: A
From Δy = λL/d, λ = Δy·d/L = 12×10-3 × 0.1×10-3 / 2 = 6×10-7 m = 600 nm. Core: invert the double-slit formula for wavelength, converting mm and nm carefully.A fixed amount of ideal gas absorbs 500 J of heat from outside and does 300 J of work on its surroundings. By how much does its internal energy change?
Correct answer: C
The first law gives ΔU = Q − W = 500 − 300 = 200 J, an increase; 800 J adds instead of subtracting. Core: ΔU = Q − W, with heat in positive and work done by the gas positive.The activity of a radioactive sample falls to 1/16 of its initial value in 24 days. What is the half-life of the nuclide?
Correct answer: D
1/16 = (1/2)4, so 24 days covers 4 half-lives and one half-life is 24/4 = 6 days. Core: count the halvings first, then divide the total time.A 100-turn square coil with sides of 0.1 m rotates at 20 rad/s about an axis perpendicular to a uniform 0.05 T magnetic field. What is the maximum EMF induced in the coil?
Correct answer: D
The coil area is A = 0.1 × 0.1 = 0.01 m2, and the peak EMF is εmax = NBAω = 100 × 0.05 × 0.01 × 20 = 1 V. Core: the generator peak EMF is εmax = NBAω.A 6 μF and a 3 μF capacitor are connected in series across a 12 V supply. How much charge is stored on the 3 μF capacitor?
Correct answer: C
The series equivalent is C = (6×3)/(6+3) = 2 μF, the total charge is Q = 2 × 12 = 24 μC, and series capacitors share the same charge, so the 3 μF also holds 24 μC; 36 μC multiplies 3 μF directly by 12 V. Core: series capacitors carry equal charge, found from the equivalent capacitance.A uniform disk flywheel of mass 8 kg and radius 0.25 m spins about its central axis at 40 rad/s. How much rotational kinetic energy does it store (for a uniform disk, I = ½MR2)?
Correct answer: E
I = ½ × 8 × 0.252 = 0.25 kg·m2, so KE = ½Iω2 = ½ × 0.25 × 1600 = 200 J; 400 J takes I as MR2. Core: first I = ½MR2, then ½Iω2.A 2 kg block slides at 10 m/s onto a rough horizontal surface (friction coefficient 0.3, g = 10 m/s2), travels 10 m, and then compresses a spring of stiffness 500 N/m. What is the maximum compression?
Correct answer: E
The initial kinetic energy ½ × 2 × 100 = 100 J minus friction work 0.3 × 2 × 10 × 10 = 60 J leaves 40 J for the spring: ½ × 500 × x2 = 40, so x = 0.4 m; 0.63 m ignores friction and 0.16 m skips the square root. Core: the full energy account is kinetic energy − friction work = spring energy.A spaceship of rest length 100 m travels at 0.8c. What length does an observer on the ground measure?
Correct answer: C
Length contraction gives L = L0√(1 − v2/c2) = 100 × √(1 − 0.64) = 100 × 0.6 = 60 m; 80 m multiplies by the raw speed fraction. Core: the length along motion contracts to L0/γ.Unified Physics Bowl specs, consistent across years.
Division 1 is for first-year physics students (no calculus); Division 2 is for second-year and AP Physics C students. The two divisions are ranked and awarded separately — students must choose one and cannot take both. Pick based on your level; our advisor can help.
Four steps · Overview / Topics / Practice / Prep
Read the 2007 Physics Bowl overview and format specs to grasp the year’s style.
Review the key topics and weights, and locate your weak areas.
Complete the 25 mock questions; submit for auto-grading and right/wrong marks.
Open the step-by-step solutions, learn from mistakes, and scan for full papers to push for national and global rankings.
Prep tips and score-boosting advice for the 2007 Physics Bowl.
The 2007 paper is plain and tidy, which makes it the right first stop for a full-year plan. Build your feel for the question types and pacing here, then move forward year by year and enjoy a smooth ramp in difficulty.
Redraw mixed series-parallel circuits in standard form on scratch paper and label the voltage and current of each element. Solving mixed circuits purely in your head invites the highest error rate, while a drawing saves checking time.
Electromagnetism and modern physics lean heavily on powers of ten, and one slipped exponent ruins a whole answer. Do a short set of notation drills weekly until separating coefficients from exponents becomes reflex.
Division 1 is for first-year students and beginners with no calculus involved; Division 2 is for second-year and AP Physics C students, ranked and awarded separately with no double entry. Registration deadlines follow the official announcement each year, so confirm your division with a teacher early.
Turn the formulas of the five blocks into cards, formula on the front, conditions and units on the back. Draw 10 cards a day; miss two in a row and reshuffle the whole box, and within two weeks the box will be error-free.
Frequent questions about the 2007 Physics Bowl papers and answers.
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