1. Recording Data

2. How to Measure Measuring instruments are common.
Ruler
Clock
Speedometer
Thermometer
Bathroom scale
All instruments have a scale.
Scale can be analog or digital
Instruments can have multiple scales

3. Analog Scales Analog scales require interpolation and rounding
Rounding when a value is taken at the nearest tick mark
Interpolation when a value is estimated between two adjacent marks

4. Digital Scales Digital scales give a direct numeric value.
Usually accurate to all digits in display.
Many provide an extra digit for rounding.
Calculators are not measuring devices.
They will give more figures than are significant.
Round to the correct number of significant figures

5. Data Tables Data is often placed in tables. Time (s) Height (m)
Columns should be labeled with measurement and units
Values should have the correct significant figures
Time (s) Height (m)

6. Graphs Both a recording tool and measuring device
Keep track of measurements as they are recorded
Estimate measurements from data on the graph
Graphs have two scales

7. Estimating from Graphs
When is the speed equal to 23 m/s?
Find the 23 m/s value
Find the intersection(s)
Find the corresponding time(s)