CBSE Class 10 Answered

Introduction:

A clinometer is a fairly simple instrument which is used to measure the angle of a slope. By using the principles of trigonometry, the height of tall objects can be calculated from the angles measured.

Clinometers are used for many things. People who work in forests use clinometers to measure the heights of trees. Builders and architects use them to measure the heights of buildings.

Clinometers are also used by surveyors to measure the steepness of slopes, or the difference between two slopes.

Other uses include working out latitude (the distance north or south of the Earth’s equator); measuring movement in buildings; monitoring the angles of the booms in cranes; checking the angle of drilling for wells; or showing the pitch and roll of a ship or plane.

Materials required:

1)    Stiff hard board

2)    Small pipe or drinking straw

3)    Thread

4)    A weight

Steps of Making

1.       Prepare a semi-circular protractor using any hard board and fix a viewing       tube (straw or pipe) along the diameter.

2.       Punch a hole (o) at the centre of the semicircle.

3.       Suspend a weight (w) from a small nail fixed to the centre.

4.       Ensure that the weight at the end of the string hangs below the protractor.

5.       Mark degrees (in sexagecimal scale with 0° at the lowest and 1° to 90° proceeding both clockwise and anticlockwise).

Working of clinometer:

Hold the straw of the clinometer to the eye level and aim the straw such that the very top of the object being measured is visible. (in the picture below it is a building) the string line will naturally fall straight down. A right triangle between the eye and the object can be observed.

Determining the height of an object:

1)       First measure the distance of the object from you.

2)       Look through the straw or pipe at the top of the object. Make sure the top of the object is clearly visible.

3)       Hold the clinometer steady and record the angle the string makes on the scale of the clinometer. To measure the angle, take the help of one of your friends.

4)       Make use of trigonometric ratios to measure the required height of the object.