NTS NAT-IM Physics Syllabus

Define acceleration and state its SI unit.

Acceleration is the rate of change of velocity with time (a = Δv/Δt); SI unit is m·s⁻².

State the three equations of motion for uniform acceleration.

v = u + at; s = ut + ½at²; v² = u² + 2as, where u = initial velocity, v = final velocity, a = acceleration, t = time, s = displacement.

For a body in free fall, what is the value of acceleration and the equation for distance fallen?

Acceleration = g ≈ 9.8 m·s⁻² (downward); distance fallen from rest h = ½gt².

On a velocity–time graph, what do the slope and the area under the graph represent?

The slope represents acceleration; the area under the graph represents displacement.

State Newton's First Law of Motion.

A body remains at rest or in uniform motion in a straight line unless acted upon by a net external force (law of inertia).

State Newton's Second Law of Motion.

The net force on a body equals the rate of change of its momentum, and for constant mass F = ma; force and acceleration are in the same direction.

State Newton's Third Law of Motion.

For every action there is an equal and opposite reaction; the two forces act on different bodies.

Define inertia and state which quantity measures it.

Inertia is a body's resistance to any change in its state of rest or motion; mass is the measure of inertia.

What is the difference between mass and weight?

Mass is the amount of matter in a body (scalar, kg, constant everywhere); weight is the gravitational force on it (vector, W = mg, in newtons, varies with g).

Define linear momentum and give its formula and SI unit.

Linear momentum is the product of mass and velocity, p = mv; it is a vector with SI unit kg·m·s⁻¹.

State the law of conservation of linear momentum.

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

What is impulse and how does it relate to momentum?

Impulse = force × time (F·Δt) and equals the change in momentum (Δp); SI unit N·s (equivalent to kg·m·s⁻¹).

Distinguish 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 (some converts to heat/deformation).

What characterizes a perfectly inelastic collision?

The colliding bodies stick together and move with a common velocity after impact; momentum is conserved but kinetic energy loss is maximum.

What are the horizontal and vertical components of velocity for a projectile launched at speed u and angle θ?

Horizontal: uₓ = u cos θ (constant); vertical: uᵧ = u sin θ (changes due to gravity).

State the formula for the time of flight of a projectile launched on level ground.

T = (2 u sin θ) / g.

State the formula for the maximum height of a projectile.

H = (u² sin²θ) / (2g).

State the formula for the horizontal range of a projectile and the angle for maximum range.

R = (u² sin 2θ) / g; maximum range occurs at θ = 45°.

What is the shape of a projectile's trajectory and why is its horizontal velocity constant?

The trajectory is a parabola; horizontal velocity is constant because there is no horizontal acceleration (neglecting air resistance), gravity acting only vertically.

Define work and give its formula and SI unit.

Work is done when a force moves its point of application: W = F d cos θ; SI unit is the joule (J = N·m). It is a scalar.

When is work done by a force zero?

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

Define kinetic energy and give its formula.

Kinetic energy is the energy a body has due to its motion: KE = ½mv²; SI unit is the joule.

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

The energy stored due to a body's position in a gravitational field: PE = mgh; SI unit is the joule.

State the work–energy theorem.

The net work done on a body equals the change in its kinetic energy: W_net = ΔKE = ½mv² − ½mu².

State the law 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 a freely falling body, how do KE and PE change while total mechanical energy stays constant?

As it falls, PE decreases and KE increases by an equal amount, so total mechanical energy (KE + PE) remains constant (ignoring air resistance).

Define power and give its formulas and SI unit.

Power is the rate of doing work: P = W/t = F·v; SI unit is the watt (W = J/s). 1 horsepower ≈ 746 W.

Define efficiency and give its formula.

Efficiency = (useful output energy or power ÷ total input energy or power) × 100%; it is always less than 100% due to energy losses (e.g., friction, heat).

In uniform circular motion, why is the body accelerating even at constant speed, and what is centripetal acceleration?

The direction of velocity continuously changes, so velocity changes and the body accelerates; centripetal acceleration a = v²/r is directed toward the centre.

State the formula for centripetal force and its direction.

F_c = mv²/r = mω²r, directed toward the centre of the circular path; it is the net force that keeps the body in circular motion.

Define angular displacement, angular velocity, and their relation to linear quantities.

Angular displacement θ (radians) is the angle swept; angular velocity ω = θ/t (rad·s⁻¹). Relations: v = rω and a_tangential = rα.

Define torque in terms of angular acceleration and state the rotational analogue of Newton's second law.

τ = Iα, where I is the moment of inertia and α is angular acceleration; this is the rotational form of F = ma.