Trigonometry in Physics
Projectile motion, inclined planes and optics.
Key idea
Projectile motion, inclined planes and optics.
In depth
Resolve forces into components, track waves, and analyse inclined planes. On a slope of angle θ, gravity splits into mg sin θ along the slope and mg cos θ into it.
Worked example
A 10 kg block on a 30° slope: along-slope force = 10 × 9.8 × 0.5 = 49 N.
Real-world uses
- Calculating projectile paths, ramps and forces on a sloping surface
Common mistake
Swapping sine and cosine for the two components.
How to learn this
- Read the key idea and say it in your own words.
- Work through the worked example, then try a similar problem.
- Use the interactive lesson’s visual and mini-quiz to check the pattern.
Frequently asked questions
What is Trigonometry in Physics?
Projectile motion, inclined planes and optics. It is a topic at the advanced level in Trigonometry.
Where is Trigonometry in Physics used in real life?
Real-world examples: Calculating projectile paths, ramps and forces on a sloping surface.
What should I learn before Trigonometry in Physics?
Make sure you are comfortable with Rotation Matrices, the previous topic in Trigonometry.
What is a common mistake with Trigonometry in Physics?
Swapping sine and cosine for the two components.
How can I practise Trigonometry in Physics?
Open the interactive lesson, play with the visual, then answer the three-question mini-quiz. Getting two right marks the topic complete.
What comes after Trigonometry in Physics?
Move on to Snell’s Law next.
Related advanced topics in Trigonometry
- Graph of Tangent – Periodic with vertical asymptotes at odd multiples of π/2.
- Phase Shift – Horizontal translation of a wave.
- Vertical Shift and Midline – Moves the wave up or down.
- General Sinusoid – Combine amplitude, period, phase and shift.
- Graphs of Reciprocal Trig Functions – Secant, cosecant and cotangent graphs.
- Pythagorean Identity – The key identity from the unit circle.