1.) Describe the proper way to use a meter stick and why this technique is necessary (include an explanation of uncertainty).
2.) What is the difference between percent error and standard error?
1) There are some useful tips at
http://www.ehow.com/how_5531166_use-meter-stick-properly.html
2) Relative error is the absolute error, divided by the correct value.
I do not know what you mean by "standard error"
For a definition of standard error, see
http://davidmlane.com/hyperstat/A103397.html
It is the random variation (standard deviation) in a series of measurements of the same thing, and is a measure of the typical absolute error in a measurement.
What is the propper handling of a meterstick?
1) To properly use a meter stick, follow these steps:
a) Ensure that the meter stick is clean, without any dirt or debris that might affect accurate measurements.
b) Align the zero mark of the meter stick with the starting point of the object you want to measure.
c) Hold the meter stick steadily, ensuring that it is parallel to the object being measured.
d) Read the value at the end of the object, making sure to align your eyes with the scale to avoid parallax error.
e) Take note of the measurement using appropriate units (e.g., centimeters or millimeters).
The technique mentioned above is necessary to obtain accurate measurements. Using a meter stick properly reduces the possibility of error in measurement. Uncertainty refers to the range within which the true value of a measurement is likely to fall. Measurements made using physical instruments, like a meter stick, have inherent uncertainties due to factors like the precision of the instrument, observational errors, and the limitations of human perception.
To determine the uncertainty associated with a meter stick, consider its smallest division or the fractional part it can be read to. For example, if the smallest division of the meter stick is 1 millimeter, then the uncertainty would be ±0.5 millimeters. This means that the actual value could be up to 0.5 millimeters more or less than the measured value. Accounting for uncertainty is crucial in scientific and engineering applications, as it provides a measure of the reliability of the measurement.
2) Percent error and standard error are two different concepts used in statistical analysis:
Percent error is a measure of the discrepancy between the measured or observed value and the true or expected value, expressed as a percentage. It indicates the relative difference between the two values. The formula for percent error is:
Percent Error = (|Observed Value - True Value| / True Value) x 100%
Percent error is commonly used in experiments or scientific studies to assess the accuracy of measurements and compare them to theoretical or expected values. It helps identify the magnitude of error and provides insights into the quality of the data obtained.
On the other hand, standard error is a measure of the precision or variability of sample statistics, typically associated with the mean. It quantifies the average difference between the mean of a sample and the true population mean. The formula for standard error depends on the type of data and the statistical analysis being employed. For example, one common formula for standard error when estimating the mean from a sample is:
Standard Error = (Standard Deviation of the Sample) / Square Root of (Sample Size)
Standard error is crucial in hypothesis testing, confidence interval estimation, and other statistical procedures. It provides an indication of the spread or dispersion of the sample data around the mean and helps assess the uncertainty associated with estimating population parameters based on the sample.