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🇵🇰 PAF Aeronautical Engineering · flashcards
PAF Aeronautical Engineering Physics Flashcards
55 question-and-answer cards covering Physics as it is examined in PAF Aeronautical Engineering. 24 of them are printed below, taken from across the deck — no signup, no paywall on the preview.
24 sample cards from the Physics deck
Sampled from the end of the deck, so these are different cards from the ones shown on the syllabus page.
State the principle of conservation of energy.
Energy can neither be created nor destroyed, only transformed from one form to another; the total energy of an isolated system remains constant.
For an object in uniform circular motion, write the formulas for centripetal acceleration and centripetal force.
Centripetal acceleration: $a_c = \frac{v^{2}}{r} = \omega^{2} r$. Centripetal force: $F_c = \frac{m v^{2}}{r} = m\omega^{2} r$, directed toward the centre.
Relate linear speed $v$ to angular velocity $\omega$, and define the period of circular motion.
$v = r\omega$, where $r$ is the radius. The period $T = \frac{2\pi}{\omega} = \frac{2\pi r}{v}$ is the time for one complete revolution.
Define linear momentum and state the law of conservation of momentum.
Linear momentum $\vec{p} = m\vec{v}$. In an isolated system (no external force), total momentum is conserved: $\sum \vec{p}_{before} = \sum \vec{p}_{after}$.
Define impulse and state the impulse-momentum theorem.
Impulse $= \vec{F}\,\Delta t$ (force times time). The impulse-momentum theorem: impulse equals change in momentum, $\vec{F}\,\Delta t = \Delta \vec{p} = m\vec{v} - m\vec{u}$.
Compare elastic and inelastic collisions.
In an elastic collision both momentum and kinetic energy are conserved. In an inelastic collision momentum is conserved but kinetic energy is not (some is converted to heat/deformation); in a perfectly inelastic collision the bodies stick together.
Define torque (moment of a force) and give its formula.
Torque is the turning effect of a force about a pivot: $\tau = F\, d = r F\sin\theta$, where $d$ is the perpendicular distance (moment arm). SI unit: $\text{N m}$.
State the principle of moments for a body in rotational equilibrium.
For a body in rotational equilibrium, the sum of clockwise moments about any point equals the sum of anticlockwise moments: $\sum \tau_{clockwise} = \sum \tau_{anticlockwise}$, i.e. net torque $= 0$.
Define the centre of gravity and the centre of mass.
Centre of gravity is the point where the whole weight of a body appears to act. Centre of mass is the point where the total mass may be considered concentrated. In a uniform gravitational field they coincide.
Define angular momentum and state its conservation law.
Angular momentum $L = I\omega$ (moment of inertia times angular velocity); for a particle $L = m v r$. When no net external torque acts, angular momentum is conserved: $I_1\omega_1 = I_2\omega_2$.
Define moment of inertia and write the rotational analogue of Newton's second law.
Moment of inertia $I = \sum m_i r_i^{2}$ measures rotational inertia about an axis. The rotational form of Newton's second law is $\tau = I\alpha$, where $\alpha$ is angular acceleration.
Define pressure in a fluid and write its dependence on depth.
Pressure $P = \frac{F}{A}$ (force per unit area). At depth $h$ in a fluid of density $\rho$: $P = \rho g h$ (gauge pressure); absolute pressure $= P_{atm} + \rho g h$. SI unit: pascal ($\text{Pa}$).
State Pascal's principle and Archimedes' principle.
Pascal's principle: pressure applied to an enclosed fluid is transmitted undiminished throughout the fluid. Archimedes' principle: the upthrust (buoyant force) on a body equals the weight of the fluid it displaces, $F_B = \rho_{fluid}\, V g$.
State the equation of continuity for an incompressible fluid and what it expresses.
$A_1 v_1 = A_2 v_2$ (or $A v = \text{constant}$). It expresses conservation of mass/volume flow rate: where the pipe is narrower the fluid flows faster.
State Bernoulli's equation for an ideal fluid.
$$P + \tfrac{1}{2}\rho v^{2} + \rho g h = \text{constant},$$ relating pressure, kinetic energy per unit volume, and potential energy per unit volume along a streamline.
Explain the Bernoulli principle in words and give one everyday application.
Where a fluid's speed is high, its pressure is low, and vice versa. Applications include aircraft lift (faster air over the wing gives lower pressure above), the carburettor, and the spin of a ball (swing/curve).
State Newton's law of universal gravitation with its formula.
Every two masses attract with a force proportional to the product of their masses and inversely proportional to the square of the distance between them: $$F = G\frac{m_1 m_2}{r^{2}},\quad G = 6.67\times10^{-11}\ \text{N m}^2\text{kg}^{-2}.$$
Derive the relation between $g$ at Earth's surface and $G$, the Earth's mass $M$ and radius $R$.
Equating $mg = G\frac{Mm}{R^{2}}$ gives $$g = \frac{GM}{R^{2}}.$$ This shows $g$ is independent of the falling object's mass.
Derive the orbital speed of a satellite in a circular orbit of radius $r$ around a planet of mass $M$.
Setting gravity as the centripetal force, $\frac{GMm}{r^{2}} = \frac{m v^{2}}{r}$, gives $$v = \sqrt{\frac{GM}{r}}.$$
What is a geostationary satellite and what is its orbital period?
A geostationary satellite orbits in the equatorial plane in the same direction as Earth's rotation with a period of $24\ \text{h}$ ($\approx 86400\ \text{s}$), so it stays fixed above one point on Earth, at an altitude of about $36000\ \text{km}$.
Define escape velocity and give its formula for Earth.
Escape velocity is the minimum speed needed to escape a planet's gravity without further propulsion: $$v_{esc} = \sqrt{\frac{2GM}{R}} = \sqrt{2gR} \approx 11.2\ \text{km s}^{-1}\ \text{for Earth}.$$
Define Simple Harmonic Motion (SHM) and write its defining equation.
SHM is oscillatory motion in which the restoring force (and acceleration) is directly proportional to the displacement and directed toward the equilibrium position: $$a = -\omega^{2} x.$$
Write the formulas for the period of a simple pendulum and a mass-spring system in SHM.
Simple pendulum: $T = 2\pi\sqrt{\dfrac{l}{g}}$. Mass-spring system: $T = 2\pi\sqrt{\dfrac{m}{k}}$, where $k$ is the spring constant.
For SHM with amplitude $x_0$ and angular frequency $\omega$, write the expressions for velocity and maximum velocity.
Velocity at displacement $x$: $v = \omega\sqrt{x_0^{2} - x^{2}}$. Maximum velocity (at equilibrium, $x = 0$): $v_{max} = \omega x_0$.
What this deck covers
The Physics deck follows the PAF Aeronautical Engineering Physics syllabus — 9 chapters and 34 topics — so questions land on material that is genuinely examinable rather than trivia around it. That works out to roughly 6.1 cards per chapter.
Answers are written to be recallable, not just readable — averaging about 180 characters, which is long enough to carry the reasoning and short enough to say out loud.
A deck like this earns its keep on the second and third pass. Read the syllabus first so you know the shape of the subject, then use the cards to find the specific facts that have not stuck.
Physics flashcards FAQ
How many Physics flashcards are in this PAF Aeronautical Engineering deck?
55 cards. This page previews 24 of them, sampled evenly across the deck so you can judge the difficulty before installing anything.
Are these PAF Aeronautical Engineering flashcards free?
Yes. The preview here is free to read with no signup, and the full 55-card deck is free inside the Examius app.
What do the Physics cards cover?
They follow the PAF Aeronautical Engineering Physics syllabus — 9 chapters and 34 topics — so the questions track what is actually examinable.
How should I use these flashcards?
Read the syllabus first so you know the shape of the subject, then drill the deck. Examius schedules each card with spaced repetition, so cards you keep missing come back sooner and ones you know drift further apart.