Given information:
- Speed of the slow-moving vehicle = 84 km/h

To find:
- Clear spacing required to overtake the slow-moving vehicle

Formula:
- Clear spacing = (Relative speed of the overtaking vehicle) × (Time taken to overtake)

Calculations:
- Let the speed of the overtaking vehicle be v km/h.
- The relative speed of the overtaking vehicle with respect to the slow-moving vehicle is (v - 84) km/h.
- To convert the relative speed from km/h to m/s, we multiply it by (5/18).

Step 1: Conversion of relative speed from km/h to m/s
- Relative speed = (v - 84) km/h × (5/18) m/s

Step 2: Calculation of time taken to overtake
- Time taken to overtake = Length of the slow-moving vehicle / Relative speed
- Let the length of the slow-moving vehicle be L meters.
- Time taken to overtake = L meters / (relative speed)

Step 3: Calculation of clear spacing
- Clear spacing = (Relative speed) × (Time taken to overtake)
- Clear spacing = [(v - 84) × (5/18)] × (L / (v - 84))
- Clear spacing = (5L / 18) meters

Final Answer:
- The slow-moving vehicle requires a clear spacing of 5L / 18 meters to overtake.

Explanation:
- The clear spacing required to overtake a vehicle depends on the relative speed of the overtaking vehicle and the time taken to overtake.
- The relative speed is the difference between the speed of the overtaking vehicle and the speed of the slow-moving vehicle.
- The time taken to overtake is the distance traveled by the overtaking vehicle divided by the relative speed.
- By substituting the relative speed and time taken to overtake in the formula, we can calculate the clear spacing required to overtake.
- In this case, the clear spacing is given by 5L / 18 meters, where L is the length of the slow-moving vehicle.
- Therefore, to overtake the slow-moving vehicle at a speed of 84 km/h, a clear spacing of 5L / 18 meters is required.