Integrated Physics Flashcards
1D Motion
- Vector: Magnitude and direction (e.g., displacement).
- Scalar: Magnitude only (e.g., distance).
- Average Velocity: v_{avg} = \frac{\Delta x}{\Delta t}
- Instantaneous Velocity: v_{inst} = \frac{dx}{dt}
- Average Acceleration: a_{avg} = \frac{\Delta v}{\Delta t}
- Instantaneous Acceleration: a_{inst} = \frac{dx}{dt}
- Final Velocity: vf = vi + a_it
- Final Displacement with Avg. Velocity: xf = xi + \frac{1}{2}(v{avg} + vi)t
- Final Displacement with Velocity and Acceleration: xf = xi + vit + \frac{1}{2}ait^2
- Final Velocity without Time: vf^2 = vi^2 + 2ai(xf - x_i)
- Freefall: Acceleration is -g (9.8 m/s^2).
Vectors and 2D Motion
- Vector Addition: Tip to Tail.
- Vector Subtraction: Add the negative (A - B = A + (-B)).
- Vector Multiplication/Division by a Scalar: Only magnitude changes; direction reverses for negative scalars.
- Vector Components:
- Length: A = \sqrt{Ax^2 + Ay^2}
- Direction: \theta = tan^{-1} \frac{Ay}{Ax}
- Unit Vectors: A = Ax\hat{i} + Ay\hat{j}
- Projectile Motion:
- Position: rf = ri + v_it + \frac{1}{2}gt^2
- Initial Horizontal Velocity: v{ix} = vi \cos \theta
- Initial Vertical Velocity: v{iy} = vi \sin \theta
- Centripetal Acceleration: a_c = \frac{v^2}{r}
- Overall Acceleration: |a| = \sqrt{at^2 + ac^2}
- Period: T = \frac{2\pi r}{v}
- Relative Velocity: r{AB} = r{AE} + v_{EB}t
Force and Motion
- Newton’s 1st Law: Object at rest stays at rest, object in motion stays in motion unless acted upon by external force.
- Newton’s 2nd Law: \Sigma F = ma
- Newton’s 3rd Law: F{12} = -F{21}
- Equilibrium: \Sigma F = 0
- Friction:
- Kinetic: F = \mu_kN
- Static: F \le \mu_sN
- Circular Motion Dynamics: F = ma_c = m \frac{v^2}{r}
Work, Energy and Power
- Scalar/Dot Product: A \cdot B = AB \cos \theta
- Work:
- Same Direction as Displacement: W = F \Delta r
- Different Direction to Displacement: W = F \Delta r \cos \theta
- Work by Varying Force: W = \int{xi}^{x_f} F dx
- Hooke’s Law: F_s = -kx
- Kinetic Energy: KE = \frac{1}{2}mv^2
- Work-Kinetic Energy Theorem: \Sigma W = \Delta KE
- Potential Energy:
- Gravitational: U = mg\Delta y
- Elastic: U = \frac{1}{2}kx^2
- Conservative Force: Work independent of path (e.g., gravity).
- Non-conservative Force: Work dependent on path (e.g., friction).
- Conservation of Energy:
- Mechanical Energy: E_{mech} = KE + U
- Total Energy: E{tot} = KE + U + E{therm}
- Non-Conservative Force Absent: \Delta E_{mech} = 0
- Non-Conservative Force Present: \Delta E_{tot} = 0
- Power: \varphi = \frac{dW}{dt}
Momentum
- Momentum: p = mv
- Impulse:
- Definition: I = \Delta p
- Constant Force: I = Ft
- Non-Constant Force: I = \int F dt
- Collisions:
- Conservation of Momentum (All Collisions): pi = pf
- Conservation of KE (Elastic Collisions): KEi = KEf
- Perfectly Inelastic: m1v{1i} + m2v{2i} = (m1 + m2)v_f
- Perfectly Elastic: m1v{1i} + m2v{2i} = m1v{1f} + m2v{2f}, \frac{1}{2}m1v{1i}^2 + \frac{1}{2}m2v{2i}^2 = \frac{1}{2}m1v{1f}^2 + \frac{1}{2}m2v{2f}^2
Rotation
- Arc Length: s = r\theta
- Translational Velocity: v = \omega r
- Translational Acceleration: a = \alpha r
- Average Angular Velocity: \omega_{avg} = \frac{\Delta \theta}{\Delta t}
- Instantaneous Angular Velocity: \omega_{inst} = \frac{d\theta}{dt}
- Instantaneous Angular Acceleration: \alpha_{inst} = \frac{d\omega}{dt}
- Final Angular Velocity: \omegaf = \omegai + \alpha t
- Final Angular Displacement: \thetaf = \thetai + \omega t + \frac{1}{2}\alpha t^2
- Final Angular Velocity without Time: \omegaf^2 = \omegai^2 + 2\alpha(\thetaf - \thetai)
- Final Angular Displacement with Avg. Velocity: \thetaf = \thetai + \frac{1}{2}(\omegai + \omegaf)t
- Kinetic Energy of Rotation: KE = \frac{\omega^2}{2} \Sigma mi ri^2
- Moment of Inertia:
- General: I = \int \rho r^2 dV
- Sphere: I = \frac{2}{5}mr^2
- Cylinder: I = \frac{1}{2}mr^2
- Disk: I = mr^2
- Parallel Axis Theorem: I = I_{CM} + MD^2
- Torque:
- Using Radius: \tau = rF\sin\phi
- Using Perpendicular Distance: \tau = Fd
- Net Torque: \Sigma \tau = I\alpha
- Angular Momentum:
- Angular Momentum: L = I\omega
- The Conservation of Momentum: Li = Lf
Waves, Oscillations and SHM
- Wave Number: k = \frac{2\pi}{\lambda}
- Wave Equation: y(x, t) = A\sin(kx - \omega t + \phi)
- Speed of Wave on a String: v = \sqrt{\frac{T}{\mu}}
- Simple Harmonic Motion:
- General Equation: x(t) = A\cos(\omega t + \phi)
- Acceleration: a_x = -\omega^2x
- Angular Frequency: \omega = \sqrt{\frac{k}{m}}
- Period: T = \frac{2\pi}{\omega}
- Frequency: f = \frac{\omega}{2\pi} = \frac{1}{T}
- Energy: E_{tot} = \frac{1}{2}kA^2
- Velocity: v = \pm \omega \sqrt{A^2 - x^2}
- SHM and Circular Motion: Uses SHM formulae for each direction of movement
- SHM and the Pendulum
- Period: T = 2\pi \sqrt{\frac{L}{g}}
- Physical Pendulum: T = 2\pi \sqrt{\frac{I}{dmg}}
Sound and EM Waves
- Bulk Modulus: B = -\frac{\Delta P}{\Delta V/V}
- Sound Wave Displacement: s(x, t) = s_{max}\cos(kx - \omega t)
- Sound Wave Pressure:
- Including Bulk Modulus: \Delta P = B s_{max}\sin(kx - \omega t)
- Without Bulk Modulus: \Delta P{max} = \rho v \omega s{max}
- Density: \rho = \frac{m}{V}
- Speed of Sound:
- Formula: v = \sqrt{\frac{B}{\rho}}
- Dependence on Temperature: v = 331 \sqrt{1 + \frac{T_c}{273}}
- EM Waves:
- Electrical Component: E = E_0\sin(kx - \omega t)
- Magnetic Component: B = B_0\sin(kx - \omega t)
- Intensity of a Sound Wave:
- Per Unit Area: I = \frac{\Delta P_{max}^2}{2\rho v}
- In Three Dimensions: I = \frac{Power_{source}}{4\pi r^2}
- Sound Levels in Decibels: \beta = 10 \log(\frac{I}{I_0})
- Doppler Effect: f' = \frac{v + vo}{v - vs}f
- Reflection of a Pulse:
- Fixed boundary: Inverted reflection.
- Free boundary: Not inverted reflection.
- Light to heavy string: Inverted reflection.
- Heavy to light string: Not inverted reflection.
- Superposition: y = 2A\sin(kx - \omega t + \frac{\phi}{2})\cos(\frac{\phi}{2})
- Interference: \frac{path \ difference}{\lambda} \times 2\pi = phase \ difference
- Standing Waves on a String:
- Formula: y = 2A\sin(kx)\cos(\omega t)
- Amplitude: amp = 2A\sin(kx)
- Nodes: x = \frac{n\lambda}{2} \ (where \ n = 0, 1, 2 …)
- Antinodes: x = \frac{n\lambda}{4} \ (where \ n = 1, 3, 5 …)
- Boundary Conditions on a String: f_n = \frac{n}{2L} \sqrt{\frac{T}{\mu}}
- Standing Waves in an Air Column:
- Closed Pipe: f_n = \frac{nv}{4L} \ (where \ n = 1, 3, 5 …)
- Open Pipe: f_n = \frac{nv}{2L} \ (where \ n = 1, 2, 3 …)
- End Effects: L = \frac{n\lambda}{2} - 2 \times end \ effects
Fluids
- Fluids at Rest:
- Density: \rho = \frac{m}{V}
- Pressure: P = \frac{F}{A}
- Pressure in Liquids: p = p_0 + \rho gd
- Gauge Pressure: p_g = p - 1atm
- Barometers: p_{atmos} = \rho gh
- Manometers: p_{gauge} = 1atm + \rho gh
- Archimedes Principle: FB = \rhof V_f g
- Fluids in Motion:
- Equation of Continuity: v1A1 = v2A2
- Bernoulli’s Equation: p1 + \frac{1}{2}\rho v1^2 + \rho gy1 = p2 + \frac{1}{2}\rho v2^2 + \rho gy2
Ray Optics
- Refraction: n1\sin\theta1 = n2\sin\theta2 \ (Snell's \ Law)
- Total Internal Reflection: \thetac = \sin^{-1}(\frac{n2}{n_1})
- Spherical Mirrors:
- Focal Length: f = \frac{1}{2}r
- Image Distance (thin lens equation): \frac{1}{P} + \frac{1}{i} = \frac{1}{f}
- Image Formation:
- Magnification: m = -\frac{i}{p}
- Thin Lens Equations:
- Focal Length: \frac{1}{f} = (n - 1)(\frac{1}{r1} - \frac{1}{r2})
- Focal Length (convex lens): \frac{1}{f} = (n - 1)\frac{1}{r_1}
- Thin Lens Equation in i: i = \frac{Pf}{P - f}
- Thin lens equation in P: P = \frac{if}{i - f}
- Magnification in terms of P and f: m = \frac{f}{P - f}
- Magnification in terms of i and f: m = \frac{i - f}{f}
- Two Lens System: m{tot} = m1m_2
- Optical Instruments:
- Simple Magnifying Lens: m_\theta = \frac{25}{f}
- Compound Microscope: m = -\frac{s}{f{obj}} \times \frac{25}{f{eye}}
- Refracting Telescope: m\theta = -\frac{f{obj}}{f_{eye}}
Wave Optics
- Path Difference:
- Constructive: \Delta r = m\lambda \ (where \ m = 1, 2, 3 …)
- Destructive: \Delta r = (m + \frac{1}{2})\lambda \ (where \ m = 1, 2, 3 …)
- Interference of Light in Double Slit:
- Angles for Bright Fringes: \theta_m = \frac{m\lambda}{d}
- Distances of Bright Fringes: y_m = \frac{L m \lambda}{d}
- Angles for Dark Fringes: \theta'_m = (m + \frac{1}{2})\frac{\lambda}{d}
- Distances of Dark Fringes: y'_m = (m + \frac{1}{2})\frac{L\lambda}{d}
- Distances Between Fringes: \Delta y = \frac{\lambda L}{d}
- Interference of Light in Single Slit:
- Angles for Dark Fringes: \theta_p = \frac{p\lambda}{a}
- Distances for Dark Fringes: y_p = \frac{p\lambda L}{a}
- Width of Central Maximum: w = \frac{2\lambda L}{a}
- Circular Aperture Diffraction: w = \frac{2.44 \lambda L}{D}
- Interferometer: d = \frac{N\lambda}{2}
Charge
- Coulomb’s Law: F = K\frac{q1q2}{r^2}
- Electrical Field:
- Vector Equation: E = \frac{F}{q}
- Electrical Field of a Point Charge: E = K\frac{q}{r^2}
- Electrical Potential: U_{elec} = Vq
Electrical Circuits
- Current:
- Definition: I = \frac{\Delta q}{\Delta t}
- Conservation of Charge: \Sigma I{in} = \Sigma I{out}
- Ohm’s Law: I = \frac{\Delta V}{R}
- Power and Energy:
- Power delivered by an emf: P_{emf} = I\E
- Power Dissipated by a Resistor: P_R = \frac{\Delta V^2}{R}