National MDCAT Physics Syllabus

Define linear momentum and give its formula and SI unit.

Momentum is the product of mass and velocity: p = mv. It is a vector. SI unit: kg·m/s.

Define impulse and state its relationship to momentum.

Impulse = force × time = F·Δt, and it equals the change in momentum: F·Δt = Δp = m(vf − vi). SI unit: N·s.

State the law of conservation of momentum.

In the absence of an external force, the total momentum of an isolated system remains constant: total momentum before = total momentum after a collision.

What is the difference between 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.

Define work and give its formula and SI unit.

Work is done when a force moves a body through a displacement: W = F d cos θ, where θ is the angle between force and displacement. SI unit: joule (J).

When is work done by a force zero?

When the displacement is zero, when the force is zero, or when the force is perpendicular to the displacement (θ = 90°, so cos θ = 0).

Define power and give its formulas and SI unit.

Power is the rate of doing work: P = W/t = F·v. SI unit: watt (W) = J/s.

Define kinetic energy and give its formula.

Kinetic energy is the energy possessed by a body due to its motion: KE = ½ m v². SI unit: joule (J).

Define gravitational potential energy (near Earth's surface) and give its formula.

Energy possessed by a body due to its position/height: PE = mgh. SI unit: joule (J).

State the work-energy theorem.

The net work done on a body equals the change in its kinetic energy: W_net = ΔKE = ½mvf² − ½mvi².

Define absolute gravitational potential energy and give its formula.

The work done in moving a body from a point to infinity (reference at infinity, where U = 0): U = −GMm/r. It is negative because gravity is attractive.

Why is absolute gravitational potential energy negative?

Because the gravitational force is attractive and the zero of potential energy is taken at infinity; work must be done against gravity to move a body to infinity, so any finite position has U < 0.

State the law of conservation of energy.

Energy can neither be created nor destroyed; it can only be transformed from one form to another, and the total energy of an isolated system remains constant.

For a freely falling body, what relationship between KE and PE follows from energy conservation?

The sum KE + PE remains constant; as the body falls, PE decreases and KE increases by an equal amount (ignoring air resistance).

What is the escape velocity formula and its approximate value for Earth?

v_esc = √(2GM/R) = √(2gR), approximately 11.2 km/s for Earth.

Define angular displacement and angular velocity with their units.

Angular displacement θ is the angle swept (radians). Angular velocity ω = θ/t (rad/s) is the rate of change of angular displacement.

What is the relationship between linear velocity and angular velocity?

v = rω, where r is the radius of the circular path.

Define angular acceleration and relate it to linear (tangential) acceleration.

Angular acceleration α = Δω/Δt (rad/s²). Tangential linear acceleration a = rα.

What is the relationship between time period T and angular velocity ω?

ω = 2π/T = 2πf, where f is the frequency.

Define centripetal force and give its formula.

The net force directed toward the center that keeps a body in circular motion: Fc = mv²/r = mrω². It is always directed toward the center.

What is centripetal acceleration and its formula?

The center-directed acceleration in circular motion: ac = v²/r = rω².

Define moment of inertia and state what it depends on.

Moment of inertia (I) is the rotational analogue of mass; it measures resistance to angular acceleration. I = Σmr². It depends on mass and its distribution relative to the axis of rotation.

Give the moment of inertia of a solid disc/cylinder and a thin hoop/ring about their central axis.

Solid disc/cylinder: I = ½MR². Thin hoop/ring: I = MR².

State the equation of continuity for fluid flow.

A1v1 = A2v2 (the product of cross-sectional area and fluid speed is constant for an incompressible fluid). It expresses conservation of mass; speed increases where area decreases.

What are the properties of an ideal fluid?

It is incompressible, non-viscous, its flow is steady (streamline), and irrotational.

What is the difference between streamline (laminar) and turbulent flow?

In streamline flow every fluid particle follows a smooth path with constant velocity at each point; in turbulent flow the motion is irregular with eddies and varying velocity.

State Bernoulli's equation.

P + ½ρv² + ρgh = constant along a streamline, expressing conservation of energy for an ideal fluid (pressure energy + kinetic energy + potential energy per unit volume).

According to Bernoulli's principle, what is the relationship between fluid speed and pressure?

Where the fluid speed is high, the pressure is low, and where the speed is low, the pressure is high (for horizontal flow).

Define viscosity and name its SI unit.

Viscosity is the internal frictional resistance of a fluid to flow (between adjacent fluid layers). SI unit of coefficient of viscosity: pascal·second (Pa·s) or N·s/m².

State Stokes' law for a sphere moving through a viscous fluid.

F = 6πηrv, where η is the coefficient of viscosity, r the sphere's radius, and v its velocity. The drag force opposes motion.

Define terminal velocity and give its formula for a sphere falling in a viscous fluid.

The constant maximum velocity reached when drag plus buoyancy balances weight: vt = 2r²(ρ − ρ₀)g / (9η), where ρ is the sphere's density and ρ₀ the fluid's density.

What is a progressive (travelling) wave, and what are the two main types?

A wave that transfers energy from one point to another through a medium. Types: transverse (particle vibration perpendicular to propagation) and longitudinal (particle vibration parallel to propagation).

State the wave equation relating speed, frequency, and wavelength.

v = fλ, where v is wave speed, f is frequency, and λ is wavelength.

How are stationary (standing) waves formed and what are nodes and antinodes?

Formed by the superposition of two identical waves travelling in opposite directions. Nodes are points of zero amplitude (no displacement); antinodes are points of maximum amplitude.

What is the distance between two consecutive nodes (or two consecutive antinodes) in a stationary wave?

λ/2 (half the wavelength). The distance between a node and the adjacent antinode is λ/4.

State two key differences between progressive and stationary waves.

Progressive waves transfer energy and all particles have the same amplitude (with phase lag); stationary waves do not transfer energy and particle amplitude varies from zero (nodes) to maximum (antinodes).