An object is moving at a constant speed along a straight line. Which of the following statements is not true? A. There must be a non-zero net force acting on the object. B. The acceleration of the object is zero. C. The net force acting on the object must be zero. D. The velocity of the object is constant. Solution It will be option A. As the object is moving with constant speed in a single direction only ,that means its velocity is constant And when it\'s velocity is constant, this means there is no acceleration of the body. When there is no net accleraccele there we\'ll be no net force acting on the body as F=ma. .