Acceleration time graph | class 9 CBSE ICSE |

when an object move in a straight line there are three types of motion that it can execute. it can be at rest, it can move with uniform velocity , it can move with non uniform velocity that is its motion is accelerated. corresponding to these three cases there are three types of graph that we can see. when the object is at rest the displacement time graph is a straight line. this is because the time will change but the displacement of the object will remain the same. when the object is moving with constant velocity that is uniform velocity or uniform motion the displacement time graph is a straight line. this is because the change of displacement in one second is constant. therefore the slope of the graph shall remain constant at every point. in this case the slope of the graph shall give us the value of velocity. in case when the object is moving with non uniform motion the velocity time graph is a curved line. this is because the velocity is not same at every point therefore the slope of the graph is different at different points. from a displacement time graph we can find the value of displacement of the particle at any given time and vice versa that is we can find the time if the displacement is provided. if the object is moving away from the reference point from which the displacement is being measured the slope of the graph will be positive. if the object is moving towards the origin the slope of the displacement time graph will be negative. when an object move with constant velocity the velocity does not change with time that why the velocity time graph becomes a straight line parallel to time axis. if the velocity is accelerated the velocity increases in constant rate that is the increase of velocity per second is fixed. the velocity time graph is a straight line inclined to the time axis. the slope of the graph gives the value of the rate of change of velocity that is the value of the acceleration. the negative slope gives the value of deceleration. if the acceleration is non uniform then the velocity time graph is a curved line. the slope of the tangent at any point gives the instantaneous acceleration at that point. the area under the velocity time graph bound by the time axis and the graph gives the value of displacement. velocity is a vector quantity. therefore it can be positive or negative. when the graph goes in the negative y axis it means that velocity is negative. thus the area beneath the time axis is negative displacement.