### Test: ACT Science

Sound waves travel through a medium by mechanically disturbing the particles of that medium. As particles in the medium are displaced by the sound wave, they in turn act upon neighboring particles. In this fashion, the wave travels through the medium through a parallel series of disturbed particles. Like in other forms of motion, the rate at which the sound wave travels can be measured by dividing the distance over which the wave travels by the time required for it to do so.

Study 1
A group of students hypothesizes that the velocity of sound is dependent upon the density of the medium through which it passes. They propose that with more matter in a given space, each particle needs to travel a shorter distance to disturb the adjacent particles. Using two microphones and a high speed recording device, the students measured the delay from the first microphone to the second. They chose a variety of media, shown in Table 1, and measured the velocity of sound through each using their two-microphone setup. The results are found in Table 1.

Study 2
The students wanted to test their hypothesis by using the same medium at different densities. To do this, they heated pure water to various temperatures and repeated the procedure described in Study 1. Their results can be found in Table 2.

 1 Suppose a second group of students hypothesizes that the velocity of sound is inversely dependent upon the density of the substance through which the sound travels. Which study would best support their hypothesis and why?

Study 1, because velocity decreases as density increases

Study 2, because velocity decreases as density increases

Study 1, because velocity decreases as density decreases

Study 2, because velocity increases as density increases

1/2 questions

0%

## Access results and powerful study features!

Take 15 seconds to create an account.