Classical Physics
Newton's laws, energy, waves, and the fundamentals of classical physics.
State Newton's Three Laws of Motion
1. An object at rest stays at rest unless acted on by a net force. 2. F = ma. 3. Every action has an equal and opposite reaction.
What is the formula for kinetic energy?
KE = ½mv² — where m is mass (kg) and v is velocity (m/s). Result in Joules.
What is the law of conservation of energy?
Energy cannot be created or destroyed, only converted from one form to another. The total energy of an isolated system remains constant.
What is the difference between speed and velocity?
Speed is a scalar (magnitude only). Velocity is a vector (magnitude + direction). E.g. 60 km/h is speed; 60 km/h north is velocity.
What is gravitational potential energy?
PE = mgh — where m is mass, g is gravitational acceleration (~9.8 m/s² on Earth), h is height above reference point.
Define work in physics
W = F·d·cos(θ) — work is done when a force causes displacement in its direction. Measured in Joules. If force is perpendicular to displacement, W = 0.
What is Hooke's Law?
F = -kx — the force exerted by a spring is proportional to its displacement x from equilibrium, where k is the spring constant (N/m).
What is the difference between elastic and inelastic collisions?
Elastic: both momentum and kinetic energy are conserved. Inelastic: momentum is conserved but KE is not (converted to heat, sound, etc.). Perfectly inelastic: objects stick together.
What is simple harmonic motion?
Oscillatory motion where the restoring force is proportional to displacement (F = -kx). Examples: pendulum (small angle), mass-spring. Period T = 2π√(m/k).
What is the Doppler effect?
The change in observed frequency of a wave when the source or observer is moving. Moving toward each other → higher pitch/frequency. Moving apart → lower pitch/frequency.