A rodding machine is positioned 30 ft away from a manhole with a 10 ft deep manhole. If 145 ft of rod is taken off the reel, how far into the sewer line is the end of the rod?

A rodding machine is positioned 30 ft away from a manhole with a 10 ft deep manhole. If 145 ft of rod is taken off the reel, how far into the sewer line is the end of the rod?

• A. 105 ft (32.0 m)
• B. 115 ft (35.1 m)
• C. 125 ft (38.1 m)
• D. 155 ft (47.2 m)

Answer: (A)

To determine how far the end of the rod extends into the sewer line, we need to consider the geometry of the situation. The rodding machine is positioned 30 feet away from the manhole, and the manhole itself is 10 feet deep. By visualizing or drawing this scenario, we can see that the rod must first go down into the manhole and then extend horizontally into the sewer line. When 145 feet of rod is taken off the reel, we first account for the vertical distance from the surface to the bottom of the manhole, which is 10 feet. This means that immediately upon inserting the rod into the manhole, 10 feet of the rod is used to reach the bottom. After the rod reaches the bottom of the manhole, what remains of the rod is calculated as follows: 145 feet (total length of rod) - 10 feet (depth of the manhole) = 135 feet. Next, we note that the rodding machine is positioned 30 feet horizontally from the manhole. The remaining length of the rod can now be extended into the sewer line horizontally. The total distance from the surface to the end of the rod can be calculated by adding the horizontal distance to the remaining length

To determine how far the end of the rod extends into the sewer line, we need to consider the geometry of the situation. The rodding machine is positioned 30 feet away from the manhole, and the manhole itself is 10 feet deep. By visualizing or drawing this scenario, we can see that the rod must first go down into the manhole and then extend horizontally into the sewer line.

When 145 feet of rod is taken off the reel, we first account for the vertical distance from the surface to the bottom of the manhole, which is 10 feet. This means that immediately upon inserting the rod into the manhole, 10 feet of the rod is used to reach the bottom.

After the rod reaches the bottom of the manhole, what remains of the rod is calculated as follows:

145 feet (total length of rod) - 10 feet (depth of the manhole) = 135 feet.

Next, we note that the rodding machine is positioned 30 feet horizontally from the manhole. The remaining length of the rod can now be extended into the sewer line horizontally. The total distance from the surface to the end of the rod can be calculated by adding the horizontal distance to the remaining length