Revision: Sound 13 Sound - Revision Quiz Test your understanding of Sound here: 1 / 5 1) Which statement explains why sound travels faster in water than in air? Water molecules are larger than air molecules. The molecules in water are closer together. Water has more energy than air. The molecules in water move faster. 2 / 5 2) Ships use sound waves to find the vertical distance to the seabed. A pulse of sound waves is sent out and echoes are detected. A ship emits a pulse of waves lasting 0.50 s. The waves have a frequency of 3600 Hz. How many complete wavelengths does the pulse contain? 7200 3600 18 000 1800 3 / 5 3) A sonar on a ship is used to find the depth of the sea. An ultrasound wave pulse is sent downwards from the ship to the sea bed. The pulse travels with a speed of 1500 m/s in sea water. If the reflected pulse is received after 1.6 s, find the depth of the sea. 1200 m 2400 m 4800 m 600 m 600 m 2400 m 4800 m 1200 m 4 / 5 4) Two sound waves are displayed on the cathode ray oscilloscope with the same settings. Which statement about the two sounds is correct? Sound 1 has a shorter wavelength than sound 2. Sound 1 is softer and at a higher pitch than sound 2. Sound 1 travels faster than sound 2. Sound 1 is softer and at a lower pitch than sound 2. 5 / 5 5) In an experiment to measure the speed of sound in air, a boy stands 40 m from a wall and bangs two pieces of wood together. At the instant he hears the echo, he bangs them together again. He does this 50 times. The time taken for 50 bangs is 12 seconds. Which calculation gives the speed of sound in air? (40 × 2 × 50)/12 (40 × 50)/12 (40 × 2 × 12)/50 12/(40 × 50) Your score is Restart quiz