The height of the building is calculated by using the formula: Note down the distance between the building and the point at which the building top is viewed through the straw. The angle of elevation is evident from the string which always acts downwards because of the pull of the weight due to gravity. Now we can use this simple device to look at the building top to measure its height.Įnsure the straw is clear and try to locate the building top through the straw. Also knot a string onto the protractor with a small weight at its other end. Just select a protractor with a small hole (usually provided at the origin) and tape a straw at its flat end. The pictures attached describe the procedure to make your own clinometer. The protractor should be as large as possible for an accurate angle observation and for further calculation. Instead it uses the accurate visual senses of the measurer. The method of measurement requires a protractor (clinometer), a straw and a measuring tape.
(Building’s shadow length/ Building’s height). (Broomstick’s shadow length/ Broomstick’s height) = Thus the height of the building can be calculated from the ratios stated below. Since both the triangles are right-angled, they become similar. Also the broomstick and its shadow form a similar right-angle triangle. The building and its shadow form a right-angle triangle. To understand the property of similar triangles, refer to the picture below. By similar triangles, we can arrive at the height of the building. Immediately measure the length of the shadow cast by the building. Now measure the height of the broomstick and the length of the shadow it casts. Erect the broomstick onto the ground vertically. This method of measurement also employs shadows but you don’t have to wait untill the length of the shadow of the broomstick equals its height. It is not always possible to use the above method due to availability of space or time. Thus, the height of the building = length of the shadow of the building. It is obvious that at this moment, the length of the shadow of the building is equal to its height.Įnsure that the length of shadow of broomstick = length of broomstick.
Measure the length of the shadow with the measuring tape. Now be patient and wait till the length of the shadow of the broomstick equals its height above the ground. Ensure that the broomstick is absolutely straight extending upwards. Place the broom stick on to the ground so it stands erect without any support. All you need is a broom stick and a measuring tape.
0 kommentar(er)
