Physics

Physics — Grade 9

American Curriculum · Ages 14-15

Ninth grade Physics is the opening course in a Physics-first sequence, an approach a growing number of districts have adopted on the argument that physics supplies the mechanical and energy concepts that chemistry and then biology depend on. The course is conceptual or lightly algebra-based, covering motion, forces, energy, momentum, waves and basic electricity.

Because it arrives before students have met trigonometry, the emphasis falls on reasoning from graphs and diagrams rather than manipulating equations — reading a velocity-time graph, drawing a free-body diagram, tracing an energy transfer. Students who build those habits early find the algebra-based course in eleventh grade a matter of adding mathematics to physics they already understand.

Key topics covered

• Motion & Graphs — Distance, displacement, speed, velocity, acceleration and motion graphs.
• Forces & Newton's Laws — Free-body diagrams, balanced and unbalanced forces, friction.
• Energy & Work — Kinetic and potential energy, work, power and conservation of energy.
• Momentum & Collisions — Impulse, conservation of momentum, elastic and inelastic collisions.
• Waves & Sound — Wave properties, reflection, refraction, frequency and pitch.
• Electricity & Magnetism — Charge, simple circuits, current, voltage and magnetic effects.
• Measurement & Lab Skills — Units, uncertainty, plotting data and drawing conclusions.