Explain any four applications of the reflection of sound.

1. 1 · Open. Sound reflects from hard surfaces; repeated reflection and echoes have many uses.
2. 2 · Write four uses.
   • Stethoscope: the heartbeat is reflected many times along the tube to the ears.
   • Megaphone: the cone reflects sound forward in one direction.
   • Sound board: a concave board with the speaker at its focus spreads sound to the audience.
   • SONAR: the ultrasonic echo from the seabed gives the depth, d = vt/2.
3. 3 · Draw, if asked. [Diagram: ship sending ultrasonic waves to the seabed and receiving the echo, with depth d marked]
4. 4 · Real-life link. Fishing boats use fish finders, and hospitals use ultrasound scans.
5. 5 · Close. Thus the reflection of sound helps in medicine, navigation and public speaking.

Scoring tip: For each use, write the device and one line on how reflection helps. Names alone get no marks.