Hint- We will use the basic definition of acceleration which states that the rate of change in velocity of an object gives the acceleration. Complete step-by-step answer: When an object moves from one point to another in a given time its velocity changes. The slope of the velocity-graph is called acceleration. Because an object goes from one point to another and the change in velocity does not remain constant. Hence, the slope of the velocity-time curve is equal to tanθ=dvdt Where θ is the angle between curve and time axis. Note- The slope of the line on a velocity-time graph reveals useful information about the acceleration of the object. If the acceleration is zero, then the slope is zero (i.e., a horizontal line). If the acceleration is positive, then the slope is positive (i.e., an upward sloping line). Also remember that the area under the velocity time graph gives the distance covered by the object.