This lab may take quite a bit of time to gather data in between rain showers.
Laboratory objective: To measure the speed of sound (mach one) by measuring the flight time for an echo.
| Location on campus | Time for 30 claps (s) | Time for one clap (echo travel time) (s) [x] | Echo flight distance (m) [y] |
|---|---|---|---|
Make an xy scatter graph of the echo travel time [x] versus the double the distance to the echo surface (y). Put the time on the x-axis, and double the distance on the y-axis.
Run an analysis of the graph using the mathematical models decision diagram. Calculate the appropriate values based on your analysis. Is there a mathematical relationship? If linear, is the intercept zero? If linear, what is the slope and intercept?
The points do not have to plot exactly on a line in order for the relationship to be linear. As long as the points scatter equally left and right of the line, do not form a curved pattern, and have a general direction then a linear regression can be calculated. If the sound generally takes more time from greater distances, then there is positive relationship between time and distance, a relationship should be calculated.
The order in which the buildings are encountered during the laboratory does not correspond with the distance to the building. Do not "connect the dots" when setting up the xy scatter graph in the graph wizard. Plot with points only, after the wizard is done add a trend line (linear regression, best fit line, also called least squares line).
The graph is a time (duration) versus space (distance) graph, the slope - if determined - is the speed of the flight of an echo. The slope is the measured speed of sound. Do research using the library or Internet to find the published (theoretical) value for the speed of sound at 28°C. Run a percentage error analysis against the published value: (measured − theoretical)/theoretical. Do NOT forget the parentheses.