Juan, Jennifer, Robert and Maria are discussing speed, velocity and acceleration. Which person's statement is true? Juan: "A car going a constant 55 mph is not accelerating when it is going around a curve." Juan: "A car going a constant 55 mph is not accelerating when it is going around a curve." Jennifer: "Velocity is only a change in distance over a period of time - like 70 mph." Jennifer: "Velocity is only a change in distance over a period of time - like 70 mph." Robert: "An object's speed is a period of time divided by distance." Robert: "An object's speed is a period of time divided by distance." Maria: "An object is accelerating when it is speeding up, slowing down, or changing direction. Maria: "An object is accelerating when it is speeding up, slowing down, or changing direction.