Ceiling Height Experiment
This experiment is to introduce significant figures, uncertainties, unit conversion and scientific notation. The first chapter of the course textbook has good brief discussions of these topics. Students are expected to take any notes they need for future reference. Students are strongly encouraged to begin each major section by writing down the section header and then recording notes underneath.


Estimate the ceiling height

 Estimate the distance from the counter top to the ceiling without the any aids such as a ruler
 Mark this estimate in your notes
 Now write down an uncertainty as to how exact you think this number is. An uncertainty is recorded as a ± to indicate the range the result can have (for example, 17 ± 3 cm means the result can actually lie between 14 and 20 centimeters)

Measure the ceiling height

 Use a single meter stick to measure the ceiling height
 Write down your best estimate in millimeters.
 How many significant figures do you think your best estimate should have?
 Write down an uncertainty as to how exact you think this measurement is.
 Convert your best estimate to feet, write down the result in scientific notation.
 Convert your uncertainty to feet. Show it to the same scientific notation as your best estimate
 Write both your result and uncertainty in feet using the format: (7.6 ± 0.3) x 10^{7} grams.
Notice the format is that the best estimate and uncertainty are within a bracket to indicate both are multiplied by the same factor of 10^{7} grams (you though are using feet).

Determine ceiling height with a laser

Caution: Do not point the laser at other student's or into your own eyes. This laser is very low power and will not cause eye damage unless pointed into an eye for several seconds. But the beam can still cause momentary blindness similar to briefly glancing at the sun. Be safe with your eyes.
Setup the small laser so that it points from one end of the bench top to the top of the pipe going into the ceiling from your bench. Use a meter stick to measure the beam height at one place. Also measure the horizontal distance from the laser to your height measurement, and laser to the pipe. You will also need to measure the height from the table top to the laser to use in your calculations.
 Draw a sketch of the experiment and indicate what was measured along with your measurements.
 Write down how exact you think each measure was
(use the ± symbol along with a value, for example ±4 cm).
 From your measurements, determine the ceiling height using similar triangles (that is the ratio of sides of a triangle is constant).
 From your measurements, determine the angle that the laser beam was making from the counter.

Summary
Complete the next part Comp Vernier Intro before writing the summary.

 Summarize all the values determined into a table
 Write a final, single sentence stating an overall ceiling height and how exact it is.

Copyright 2020 by Capilano University Physics Dept.