physics lab reports
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MeasurementsofLengthMassandTime1.docx
Measurement: Length, Mass, Volume, Density, and Time
Measurements of Length, Mass and Time
NAME:
Instructor:
Abstract;
It should be ½ to 1 page long
1. Length
· Estimate the length of a meter by putting a pen or pencil at one end of a table and placing a second
pen or pencil about one meter away from the first.
· Use the meter tape measure to measure the actual length of your meter estimate.
· Record the length of your meter estimate.
· Calculate the percent error of your estimated meter from an actual meter.
2. Time
· Estimate a 30-s time period while someone else times you using a stopwatch. (If you do not have a
partner, you can do this experiment by closing your eyes; start the stopwatch and stop it when you
think 30 s have elapsed.)
· Record the actual time of your estimate.
· Calculate the percent error of the estimate from the actual time.
3. Mass
· Pick up a small paperback book or similar small object and estimate its mass.
· Determine the actual mass of the object using the 500-g spring scale.
· Record the estimated mass and the actual mass and calculate the percent error.
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Data Table 1: Estimation of various measurements |
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Measurement |
Estimated |
Actual |
% Error |
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Length (m) |
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Time (s) |
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Mass (kg) |
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In this exercise you will use your hand, a ruler or a tape measure to measure lengths of objects.
You will then compare the precision of these different methods.
Hand width (Measurement of your hand span) ________ cm_______ m
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Data Table 2: Measurement of width and height of a door |
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Instrument used |
Width (cm) |
Width (m) |
Height (cm) |
Height (m) |
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Ruler or meter tape |
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Hand unit* |
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* hand units x hand width
In this exercise you will use a stop watch and different cues to measure time.
· Measure and mark a vertical distance of 2 m from the floor up.
· Stand on a chair and hold a ball (marble) at the marked height in one hand and the stopwatch in the other hand.
· Start your stopwatch at the same instant you release the object and stop the timer when you see the object hit the floor.
· Repeat five times and calculate the average.
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Data Table 5: Time measurements using visual cues |
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Drop time (s) |
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Trial 1 |
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Trial 2 |
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Trial 3
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Trial 4 |
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Trial 5 |
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Average |
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· Let somebody time you while you drop the ball – use verbal commands like “start” or “now” to synchronize the dropping and timing. If you do not have a partner, you can do this experiment by closing your eyes; start the stopwatch and stop it when you think 30 s have elapsed.)
· Repeat 5 times, find the average drop time of the object.
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Data Table 6: Time measurements using auditory cues |
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Drop time (s) |
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Trial 1 |
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Trial 2 |
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Trial 3 |
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Trial 4 |
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Trial 5 |
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Average |
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In Data Table 7 include your measurements of round shaped objects around the lab using string, ruler or meter tape
Data Table 6
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Object |
Diameter D (m) |
Circumference C (m) |
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Graphing data and the determination of π based on the values from Data Table 7
The relationship between the circumference, C and the diameter, D of a circle is: C= π D
-Graph C vs. d using a computer spreadsheet program then insert the graph below.
C- circumference on the Y axis and D- diameter on X axis
OR
-Draw the graph on a separate piece of paper and include the picture of your graph below.
The graph should be a line; use “best fit line” do not simply connect the points, representing experimental value of ”π”.
Questions
1. What are the SI units for length, time, and mass?
2. Can you think of an occasion when it would be adequate to use your “hand” measurement?
3. Calculate the exact time it takes a ball to fall from 2m to the ground using the following equation:, g=9.8m/s2 represents acceleration due to gravity on Earth. Which of the time measurements (tables 5 and 6) is more accurate when you compare it with the exact value of time?
3. How much is the slope of the graph generated from data table 6?
4. Calculate the percentage error for the mathematical value calculated using π=3.1415 for the accepted value.
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