Sci-Tech Labs: Clinometer

Video Description -- Clinometer In this activity, you can build a protractor clinometer to find the height of an object. Materials • 1 Semi-Circular Protractor -- if possible, find a protractor with a small hole in the middle of the flat side. If you were to lay the flat side down on a flat surface, the hole line up with the 90 degree mark. • 1 Hex Nut • 1 Straw • 1 pair of scissors • 1 calculator • 1 measuring tape • Recording instruments (paper/pencil) • Several inches of string • Tape Procedure 1) (Optional) If finding the protractor listed above is not possible, you can print a paper protractor. After cutting the paper protractor out, you will need to make a small hole through the middle of the flat side. Alternatively, you can also tape the string to that point. 2) Tie one end of the string through your hex nut. This will be your weight. 3) Tie the other end of the string through the small hole of the protractor. 4) If you have a bendy straw, cut off the bending joint. You will use the longer portion. 5) Tape the cut straw on to the protractor's flat side parallel to the edge. This means the straw should line up with both "0" angles. The straw will be your scope. 6) To use the clinometer you made, find something you would like to measure. 7) Place the clinometer to your eye so that you can see through the straw and so that the curved portion is facing downwards. The string should be going straight down as well. 8) Aim your scope to the height of the object you would like to measure. 9) Once you line up the top of the object with the scope, pinch the string at the angle it is falling on. 10) Record the angle the string was at. 11) Subtract 90 from that angle. 12) Measure the height of your eye from the ground up with the measuring tape. 13) Record the height of your eye. 14) Now you need the distance of the object from where you were standing. Use the measuring tape if you're close enough. 15) Record the distance you are from the object. 16) Use the mathematical equation below to find the height of the object. Height of object = (height of your eye) + tan (angle from your eye to object) X (horizontal distance from you to object) Helpful notes for using the clinometer • Use the clinometer on objects that are taller than you are. • The process is much easier with two people. One person can sight the object while the other records. Clinometer Info • If what you are looking at is taller than you, the angle from your eye to the top of the object is called the "angle of elevation". If you are looking at something smaller, the angle from your eye to the top of the object is called the "angle of depression". • Clinometers (also known as inclinometer and klinometer) are used for a variety of things that include finding how tall something is. This list includes things such as star spotting, surveying, video games, navigation, and boat making. • The math used is called trigonometry.