How sound is produced and travels, pitch and loudness, the speed of sound and echo calculations, evidence that sound waves reflect, refract, diffract and interfere, and the uses of ultrasound.
5 narrated scenes. Press play, listen and read along — the points appear as they are explained. Use ‹ Prev / Next › or the scene bar to jump to any scene.
Lightning flashes first and thunder rumbles later. That gap is a stopwatch for measuring how far away the storm is.
Narration uses your device’s built-in voice. No sound? Switch to “Captions only” — the captions advance on their own.
Sound is a longitudinal wave of compressions and rarefactions.
Copy these into your notebook in your own words — that is how they stick.
Produced by vibrations; longitudinal wave; needs a medium.
Solids > liquids > gases; about 340 m/s in air.
Depends on frequency.
Depends on amplitude.
About 20 Hz – 20 000 Hz.
d = vt ÷ 2 (sound goes there and back).
Reflection (echo), refraction, diffraction (round corners), interference.
Above 20 000 Hz: pre-natal scans, flaw detection, sonar, cleaning.
3 quick games on this lesson. Earn XP and badges as you play — your best score for each game is saved. Games are for practice and do not change your exam readiness. More games in the Physics Arcade.
8 items modelled on real CSEC Paper 1 questions. Choose one answer for each, then check. Aim for 80% or better. Work each item on paper first.
Write full answers, then reveal the mark scheme and tick the points you earned (14 marks in total). Show all your working — method marks count. Your answers are saved on this device.
Question 1 [14 marks]
Take the speed of sound in air as 340 m/s.
(a) (a) Describe how a sound wave is produced and travels through air. [3]
(b) (b) State the range of frequencies audible to a normal human ear. [1]
(c) (c) A student claps and hears an echo from a wall 0.40 s later. Calculate the distance to the wall. [3]
(d) (d) Explain why a bat can find its prey in the dark using ultrasound. [2]
(e) (e) Name two uses of ultrasound. [2]
(f) (f) State one piece of evidence that sound diffracts. [1]
(g) (g) Explain, in terms of wave properties, why a high note from a flute is different from a low note. [2]
Find these in your own past-paper booklets for extra timed practice. Items above are written in the style of these papers; any adapted from a specific question say so.