Physics Made Easy: Light, Lenses & Electricity

Define work as the force that produces displacement. Displacement determines whether work occurs, and w = f × s; SI and CGS units include joule and erg.

Define energy as the capacity to do work, explain joule and erg units, show energy's relation to work with examples, and outline forms like heat, tidal, chemical, and kinetic energy.

Explore kinetic energy and gravitational potential energy, and learn how mass, height, and gravity govern energy transfer and the conservation of energy via mgh and 1/2 m v^2.

Explore balanced and unbalanced forces with examples like tug of war and friction, showing equilibrium yields no motion and unbalanced forces cause acceleration.

Explore how motion is relative, defined through inertial frames of reference, and learn types like rectilinear, curvilinear, translatory, rotational, oscillatory, vibratory, periodic, and uniform versus non uniform motion.

Take a quick motion quiz that reinforces relative motion and inertial frames, using Ben on a couch and channel-based motion types to identify correct motions.

Learn how distance and displacement differ, and how scalars differ from vectors, with examples of speed, velocity, and acceleration in motion, including rectilinear, rotational, and oscillatory motion.

Explore scalars and vectors and how distance, displacement, speed, velocity, and acceleration relate. See why constant speed on a circular track still causes acceleration due to changing direction.

Explore how light is electromagnetic radiation and map the spectrum from radio to gamma rays. Learn how wavelength, frequency, and energy distinguish each type, while all share the same speed.

Explore how prisms disperse white light into a rainbow through refraction and dispersion via wavelength dependence, and how scattering creates blue skies and red sunsets.

Trace the evolution of mirrors from still-water reflections to obsidian, polished metals, and glass, highlighting improvements in reflectance and the rise of silvered mirrors used in space tech.

Explore how light reflects off surfaces, applying the laws of reflection, and how plane, concave, and convex mirrors shape images through specular and diffuse reflections.

Explore how plane mirrors demonstrate reflection by producing virtual, upright images of the same size at equal object distance, with lateral inversion and axis of symmetry.

Explore how two rays from an object reflect in a plane mirror to form a virtual image behind the mirror, which is upright, same size, and equally distant.

Compare spherical mirrors—concave and convex—and explain how parallel light focuses (real) or diverges while defining center of curvature, radius, pole, and focal length.

Explore how convex and concave mirrors form images using the mirror formula, magnification, and sign conventions, and determine object and image distances and focal lengths.

Explore how refraction bends light through convex and concave spherical lenses. See how focal length and the optical axis govern image formation.

Explore the lens formula and magnification to predict image distance and size for convex and concave lenses, with sign conventions and real versus virtual images.

Explore natural light: bioluminescent dinoflagellates and the sun's all-wavelength emission. Distinguish natural vs artificial sources and apply quiz insights on visible energy and X-rays to UV currency detection.

Explain how specular and diffuse reflection arise from surface roughness relative to light wavelength, and how polishing surfaces yields mirror-like reflections.

Explore scalars and vectors, and understand distance, displacement, speed, velocity, and acceleration, including how direction changes imply acceleration in circular motion.

Explore electricity and electrical energy, and how electric current powers appliances through heating, magnetic, and chemical effects, including electroplating, within a closed circuit.

Explore the history of electricity from ancient shocks and amber to William Gilberg’s naming and Benjamin Franklin’s kite experiment, and learn how batteries power portable electricity in modern devices.

Explore how electricity originates from renewable and non-renewable energy sources, and how generators convert turbine motion from coal, wind, hydro, solar, and nuclear plants into electrical energy.