Elementary Physics

  1. If a particle undergoes simple vibrations with an amplitude of distance A, what is the distance it travels in one period? (Note — this is just a vibrating particle. There is no WAVE present. If you answer using a diagram, explain what the diagram is, and label any axes.)
  2. A water wave has a wavelength of 12 cm and a speed of 50 cm/s. What is the frequency?
  3. If an earthquake wave travels with a speed of 5.0 km/s, what is its wavelength if the wave’s frequency is 50 Hz?
  4. A hiker wants to determine the length of a lake by shouting and listening for an echo from the cliff at the far end. If the echo returns after 2 seconds, how long is the lake? Assume the speed of sound in air is 340 m/s. (If it will help you, you may draw a diagram.)

Sample Solution