Step 1: Identify the formula for escape velocity, which is Escape velocity = √(2GM/R).
Step 2: Identify the values needed for the formula: G = 6.67 × 10^-11 N m²/kg², M = 6 × 10^24 kg, and R = 4,000 km (which needs to be converted to meters).
Step 3: Convert the radius from kilometers to meters: 4,000 km = 4 × 10^6 m.
Step 4: Substitute the values into the formula: Escape velocity = √(2 * 6.67 × 10^-11 * 6 × 10^24 / 4 × 10^6).