To find the initial speed of the smaller car, we apply the law of conservation of momentum, which states that the total momentum before a collision is equal to the total momentum after the collision. The momentum of an object is calculated as the product of its mass and velocity. Before the collision, the momentum of the smaller car is given by its mass (1000 kg) multiplied by its initial speed (v), while the SUV, being at rest, contributes no momentum (0). After the collision, the two vehicles stick together, resulting in a combined mass of 1000 kg + 2200 kg, moving at a final speed of 4.7 m/s. Setting up the equation: 1000 kg * v = (1000 kg + 2200 kg) * 4.7 m/s. Solving for v gives us v = (3200 kg * 4.7 m/s) / 1000 kg = 15 m/s. Thus, the initial speed of the smaller car was 15 m/s.