Physics Class 11

Kinematics

• Displacement: Change in position of an object (Δx = x2 - x1)
• Velocity: Rate of change of displacement (v = Δx / Δt)
• Acceleration: Rate of change of velocity (a = Δv / Δt)
• Motion graphs: Position-time, velocity-time, and acceleration-time graphs
• Equations of motion:
  1. v = u + at
  2. s = ut + (1/2)at^2
  3. v^2 = u^2 + 2as

Dynamics

• Force: Push or pull that causes an object to change its motion
• Newton's laws:
  1. First law: Inertia - an object at rest remains at rest, an object in motion remains in motion
  2. Second law: F = ma (force is equal to mass times acceleration)
  3. Third law: Action and reaction forces are equal and opposite
• Types of forces:
  • Gravity (Fg = mg)
  • Friction (Fs = μN)
  • Normal force (Fn = mg)
  • Tension (Ft =?)

Energy and Work

• Kinetic energy: Energy of motion (K = 1/2mv^2)
• Potential energy: Energy of position (U = mgh)
• Total energy: Sum of kinetic and potential energies (E = K + U)
• Work: Force applied over a distance (W = Fs)
• Efficiency: Ratio of output energy to input energy (η = W_out / W_in)

Rotational Motion

• Angular displacement: Change in angle of an object (Δθ = θ2 - θ1)
• Angular velocity: Rate of change of angular displacement (ω = Δθ / Δt)
• Angular acceleration: Rate of change of angular velocity (α = Δω / Δt)
• Rotational kinematics equations:
  1. ω = ω0 + αt
  2. θ = ω0t + (1/2)αt^2
  3. ω^2 = ω0^2 + 2αθ

Oscillations and Waves

• Simple harmonic motion: Periodic motion with a constant amplitude (A) and frequency (f)
• Types of waves:
  • Mechanical waves (require a medium)
  • Electromagnetic waves (do not require a medium)
• Wave properties:
  • Amplitude (A)
  • Frequency (f)
  • Wavelength (λ)
  • Speed (v)