# 6 Physics questions

1a)There is a sound that is produced. You record its intensity from two positions, position 1 and position 2. The intensity of the sound at position 1 is higher than position 2. At which position is the amplitude of the sound larger?
1b) The intensity of a sound when you are 5 ft from it is 0.02 W/m2. How intense is the same sound if you move 10 ft away?
1c)The intensity of a sound when you are 3 ft from the source is 5×10-4 W/m2. If you move to a new position and the intensity is 2×10-3, what is your new position?
2.)As you get further away from the source of a sound, what happens to the intensity of that sound? What happens to the energy of the sound? What happens to the amplitude of the sound?
3.)You have two ripples in a pond that interfere with each other. Where will the nodal lines occur? What is the phase of the two waves when there are nodal lines? At what points will the system of the two interfering waves have the maximum energy?
4.) You increase the intensity of a sound to four times its original value (in other words, the new sound is 4x more intense). lHow much larger is the new amplitude of the sound wave? (Might help to use sample numbers in the formula).
5.) You are studying the first normal mode of a string fixed at both ends. It is a conservative system. When does the antinode have maximum kinetic energy? When does the antinode have maximum potential energy?
A string is disturbed from equilibrium so that a single crest travels along it. When does the string have kinetic energy? When does the string have potential energy? If it is a conservative system, what factors affect the energy of the wave pulse?
6.)Give an example of an object that has potential energy. Give an example of an object that has kinetic energy.