C. Unsolved numerical question

Try these first

1. 1.

   What is EDM and how does it work?

   Hint

   Think about how sound travels.

2. 2.

   Why do we need to correct for the heights of instruments?

   Hint

   Consider the physical positions of the EDM and the reflector.

3. 3.

   What does EDM stand for?

   • Electronic Distance Measurement
   • Electronic Dimension Measurement
   • Extended Duration Measurement

   Hint

   Think about the purpose of EDM.

4. 4.

   True or False: The vertical angle is not important when calculating horizontal distance.

   • True
   • False

   Hint

   Reflect on the role of angles in trigonometry.

5. 5.

   A surveyor measures a slope of 1000 m at a height of 3 m and has a vertical angle of 7°. Calculate the horizontal distance.

   Hint

   Use a scientific calculator for trig functions.

6. 6.

   If an EDM measures a distance of 500 m at a height of 1.5 m above ground, what is the horizontal distance when the vertical angle is 2°?

   Hint

   First calculate the cosine, then adjust for height.