## Step-by-Step Solution ### **Given:** - **Gross weight of vehicle:** 30,000 kg - **Total resistance:** 20% --- ### **Step 1: Locate the Gross Weight** - The graph's top axis is labeled **Gross weight (kg x 100)**. - **30,000 kg** = **30** on the axis (kg × 100). --- ### **Step 2: Locate the Resistance Line** - The right side of the graph has **Total resistance** lines (grade + rolling) in %. - Find the **20% resistance** line. --- ### **Step 3: Find the Intersection** - Follow the **20% resistance line** downwards. - Find where it crosses the **vertical line for 30,000 kg** gross weight. --- ### **Step 4: Find the Maximum Speed** - At the intersection of the **20% resistance line** and **30,000 kg** (or close to the load curve marked 34,020 kg), look horizontally to the left until you hit the **performance curve** for the vehicle (the solid direct drive curve). - From this intersection, drop vertically down to the **Speed** axis at the bottom (in km/h and mph). --- ### **Step 5: Read the Maximum Speed** - The intersection is just before the 8th gear curve ends. - The **speed axis** shows values in **km/h (bottom)** and **mph (top)**. #### **Estimation:** - The intersection point is **a little above 20 mph**, which is about **35 km/h**. --- ## **Final Answer** ### **The maximum speed of the vehicle at 30,000 kg gross weight and 20% total resistance is:** **Maximum Speed ≈ 35 km/h** (or about **22 mph**) --- **Explanation:** At 30,000 kg and 20% resistance, the 20% resistance line crosses the vehicle performance curve at roughly 35 km/h. This is the fastest speed the vehicle can maintain under those conditions.