A 300 m straight race is started by firing a starter pistol, which produces a puff of smoke and a loud bang at the same time. A finishing judge stands at the finish line, 300 m away from the starter. When does the finishing judge see the smoke and when does he hear the bang? (Assume the speed of sound in air is 330 m/s and the speed of light is 3.0 × 108 m/s).
Sees the smoke: almost immediately; Hears the bang: almost immediately
Sees the smoke: almost immediately; Hears the bang: after about 0.9 s0.9\text{ s}0.9 s
Sees the smoke: after about 0.9 s0.9\text{ s}0.9 s; Hears the bang: almost immediately
Sees the smoke: after about 0.9 s0.9\text{ s}0.9 s; Hears the bang: after about 0.9 s0.9\text{ s}0.9 s
295 exam-style questions on CIE IGCSE Physics Sound, covering Sound. Each one has a worked solution and a mark scheme showing where the marks go.