ICS (Intermediate in Computer Science) Physics (Part I) - Elective Flashcards

24 sample cards from the Physics (Part I) - Elective deck

Sampled from the end of the deck, so these are different cards from the ones shown on the syllabus page.

1. What is the dimension of work/energy, and of power?

   Work/energy = [ML²T⁻²]; power = [ML²T⁻³].

2. State the head-to-tail (graphical) rule for adding vectors.

   Draw the vectors so that the tail of each successive vector starts at the head of the previous one; the resultant is drawn from the tail of the first vector to the head of the last.

3. How do you find the magnitude and direction of the resultant of two perpendicular vectors A and B?

   Magnitude R = √(A² + B²); direction θ = tan⁻¹(B/A) measured from vector A.

4. What are the rectangular components of a vector A making angle θ with the x-axis?

   Aₓ = A cos θ (horizontal component) and Aᵧ = A sin θ (vertical component).

5. How do you reconstruct a vector from its rectangular components Aₓ and Aᵧ?

   Magnitude A = √(Aₓ² + Aᵧ²); direction θ = tan⁻¹(Aᵧ/Aₓ).

6. Define the scalar (dot) product of two vectors.

   A·B = AB cos θ, where θ is the angle between them. The result is a scalar.

7. What are the dot products of the unit vectors î, ĵ, k̂ with themselves and with each other?

   î·î = ĵ·ĵ = k̂·k̂ = 1; î·ĵ = ĵ·k̂ = k̂·î = 0.

8. Define the vector (cross) product of two vectors.

   A×B = AB sin θ n̂, where θ is the angle between them and n̂ is a unit vector perpendicular to both, given by the right-hand rule. The result is a vector.

9. What are the cross products î×ĵ, ĵ×k̂, and k̂×î?

   î×ĵ = k̂, ĵ×k̂ = î, k̂×î = ĵ (and reversing the order gives the negative).

10. Is the cross product commutative? What property does it have instead?

    No. The cross product is anti-commutative: A×B = −(B×A).

11. Give one physical example each of a scalar product and a vector product.

    Scalar product: work W = F·d. Vector product: torque τ = r×F (also angular momentum and magnetic force).

12. Define torque (moment of a force).

    The turning effect of a force about a point or axis. τ = r × F, magnitude τ = rF sin θ; SI unit is the newton·metre (N·m).

13. State the first condition of equilibrium.

    The vector sum of all forces acting on the body is zero: ΣFₓ = 0 and ΣFᵧ = 0 (no linear acceleration).

14. State the second condition of equilibrium.

    The sum of all torques (clockwise and anticlockwise) acting on the body about any point is zero: Στ = 0 (no angular acceleration).

15. What is the difference between displacement and distance?

    Distance is the total path length covered (a scalar). Displacement is the shortest straight-line directed distance from start to finish (a vector).

16. Define velocity and acceleration.

    Velocity is the rate of change of displacement (a vector). Acceleration is the rate of change of velocity (a vector).

17. Write the three equations of uniformly accelerated motion.

    vf = vi + at; S = vi·t + ½at²; 2aS = vf² − vi².

18. 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 (the law of inertia).

19. State Newton's second law of motion.

    The rate of change of momentum of a body is directly proportional to the applied force and acts in the direction of that force: F = ma.

20. State Newton's third law of motion.

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

21. Define linear momentum and give its SI unit.

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

22. Define impulse and state the impulse–momentum theorem.

    Impulse = F·t (force × time it acts). The impulse–momentum theorem states impulse equals the change in momentum: F·t = mvf − mvi. SI unit: N·s.

23. State the law of conservation of momentum.

    In the absence of an external force, the total momentum of an isolated system remains constant: m₁u₁ + m₂u₂ = m₁v₁ + m₂v₂.

24. In projectile motion, what are the horizontal and vertical components of the initial velocity, and how do they behave?

    Horizontal: vₓ = vi cos θ, constant (no acceleration). Vertical: vᵧ = vi sin θ, changing due to gravity g. Time of flight T = 2vi sinθ / g, maximum height H = (vi² sin²θ)/2g, and range R = (vi² sin2θ)/g, which is maximum at θ = 45°.

What this deck covers

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