Question

The R.L. of the floor of a factory is 30.500. Staff reading on the floor is 1.610 m and staff reading when the staff is held inverted with the bottom touching the tie beam of the roof truss is 3.700 m. Find the height of the tie beam above the floor.

• A. 6.310 m
• B. 5.310 m
• C. 7.310 m
• D. 4.310 m

Hint:

When the staff is held inverted, the reading increases. Use the difference in readings to calculate the height of the object above the reference point.

Answer 1

The Correct Option is A

Step 1: Understanding the Problem.
The Reduced Level (R.L.) of the floor is 30.500 m. The staff reading on the floor is 1.610 m. The staff reading when the staff is held inverted with the bottom touching the tie beam is 3.700 m. We need to find the height of the tie beam above the floor.
Step 2: Calculating the Height of the Tie Beam.
The height of the tie beam above the floor is given by the difference in the two staff readings, added to the R.L. of the floor. The difference in the staff readings is: \[ \text{Difference in readings} = 3.700 - 1.610 = 2.090 \, \text{m}. \] The height of the tie beam is: \[ \text{Height of tie beam} = 30.500 + 2.090 = 6.310 \, \text{m}. \]
Step 3: Conclusion.
Therefore, the height of the tie beam above the floor is 6.310 m, making option (1) the correct answer.

Final Answer: \[ \boxed{6.310 \, \text{m}} \]