Physics Cheatsheet
Basic Concepts
- Scalars: Physical quantities with only magnitude (e.g., mass, time, temperature)
- Vectors: Physical quantities with both magnitude and direction (e.g., velocity, force, displacement)
- Kinematics: The study of motion without considering its causes (e.g., position, velocity, acceleration)
- Dynamics: The study of the causes of motion (e.g., forces, energy, momentum)
- Work: The product of force and displacement in the direction of the force
- Energy: The ability to do work
- Power: The rate at which work is done
Laws and Principles
- Newton’s Laws of Motion:
- An object will remain at rest or in uniform motion in a straight line unless acted upon by an external force.
- The rate of change of momentum of an object is directly proportional to the force applied, and takes place in the direction in which the force is applied.
- For every action, there is an equal and opposite reaction.
- Law of Conservation of Energy: Energy cannot be created or destroyed, only transferred or converted from one form to another.
- Law of Conservation of Momentum: In the absence of external forces, the total momentum of a system remains constant.
- Second Law of Thermodynamics: In any natural process, the total entropy of a closed system always increases over time.
Equations
- Kinematics:
- Average velocity: v = Δx / Δt
- Average acceleration: a = Δv / Δt
- Final velocity: vf = vi + at
- Displacement: Δx = vavg * t
- Final velocity squared: vf^2 = vi^2 + 2aΔx
- Dynamics:
- Force: F = ma
- Weight: w = mg
- Work: W = Fd cos(θ)
- Kinetic energy: K = (1/2)mv^2
- Potential energy: U = mgh
- Power: P = W / t
- Thermodynamics:
- First Law: ΔU = Q - W
- Efficiency: η = W / Qh
Symbols and Units
- Common Symbols:
- v: velocity
- a: acceleration
- F: force
- m: mass
- g: acceleration due to gravity
- Δx: displacement
- t: time
- Q: heat
- W: work
- θ: angle
- Common Units:
- Length: meter (m)
- Time: second (s)
- Mass: kilogram (kg)
- Velocity: meter per second (m/s)
- Acceleration: meter per second squared (m/s^2)
- Force: newton (N)
- Work and energy: joule (J)
- Power: watt (W)
- Temperature: Kelvin (K)
- Heat: calorie (cal)
Resources