how To find the height of a building using Clinometer.
Answers
Answer:
To use the clinometer:
The diagram shows what the assembled clinometer will look like when laying an a flat surface. When using it, the straw will be on the top.
You will need two people: one to look through the straw and site the top of an object and one to read the degrees that the string makes with the protractor.
Find a tall tree (or building, flag pole etc.) in a place where there is plenty of space to move away from the object that you are measuring.
Look through the staw and find the top of the tree.
Ask your friend to read the angle being recorded on the clinometer. This is read where the string or cotton is touching the protractor.
Keep moving back (or forward if you've gone too far) until you have the clinometer angle measuring 45 degrees. With a 45 degree angle your job will be much easier as the distance from you to the tree will be equal to the distance from the ground to the top of the tree.
Measure the distance between where you are standing and the base of the tree.
Measure the distance from your eyes to the ground (this is where your partner is indispensible!)
Add these two distances together - because to be most accurate the triangle has to finish at your feet not your eyes.
You now have a very close approximation of the height of the tree, building or other tall structure.
You, the base of the tree and the top of the tree, form an isosceles triangle meaning the distance from you to the base of the tree is equal to the height of the tree (from the viewer's eyes to the top).
Materials Required:
Clinometer
Tape measure
Paper
Pen or pencil
Assistant
Step 1: Pick a spot
Pick a spot to measure your object . You should be far enough
away from your object that you can see the top of it, and you need to be on level ground with the base of the object.
Step 2: Measure angle
Here's where we bust out our handy clinometer. Look through the straw of your clinometer at the top of the light pole (or whatever object you're measuring). The weighted string should hang down freely, crossing the protractor portion of the clinometer. Read the angle shown, and subtract from 90° to find your angle of vision from your eye to the top of the pole (it can be helpful here to have an assistant to read the measurement while you look through the straw).
Record your results on your paper.
Step 3: Measure distance
Once you have your angle of vision, use your tape measure to find the distance from the spot you're standing to the base of the object you're measuring (an assistant comes in handy here, too). We must know how far away you are to accurately calculate the height.
Step 4: Find your eye-height
The last piece of data you need to calculate the height of your object is the height from the ground to your eye (your eye height). Have your assistant help you measure this using your tape measure.
Step 5: Draw a picture
Time to move inside. In calculating the height of the object you just measured, I find it helpful to begin by drawing a picture and labeling it with all of the information we have.
Step 6: Model as a triangle
The next step is to simplify your drawing to model your system as a right triangle. Label your triangle with the angle you read on your clinometer as well as the distance you were standing from the object (we don't need the eye height just yet).
Step 7: Solve for x
We can find x in this triangle (which represents the portion of the height from eye-level up) by using some basic trigonometry, specifically the tangent ratio of the triangle:
tan(angle) = x / distance
Multiply by the distance on both sides and you get:
x = tan(angle) * distance
Use a calculator to multiply these together and get a decimal value (be sure your calculator is in degrees mode, rather than radians.
Step 8: Combine with eye height
To find the height of your object, bring this x value back to the original drawing. By labeling it, we can see that the height of the object, h, is equal to the x value we just found plus the eye-height we measured earlier:
h = x + (eye-height)