## Velocity-time graph

Velocity-time graph of various types of motion of a body.

1. When a body is moving with a constant velocity, the velocity-time graph is a straight line AB parallel to time axis.

The slope of velocity-time curve (representing the instantaneous acceleration) is zero.

1. When a body is moving with a constant acceleration and its initial velocity is zero, the velocity-time curve is an oblique straight line, passing through origin.

Greater will be the slope of straight line OA, greater will be the instantaneous acceleration.

1. When a body is moving with a constant acceleration and its initial velocity is not zero, the velocity-time curve is an oblique straight line AB not passing through origin.

A) Here OA represents the instant velocity of the boy.

B) The area enclosed by the velocity-time figure with time axis represents the distance traveled by the body.

1. When a body is moving with a constant retardation and its initial velocity is not zero, the velocity-time curve is an oblique straight line AB not passing through origin.

The slope of straight line with time axis, makes an angle θ>90⁰.

1. When a body is moving with increasing acceleration, the velocity-time curve is a curve with bend upwards.

The slope of velocity-time curve (i.e. instantaneous acceleration) increases with time.

1. When a body is moving with decreasing acceleration, the velocity-time graph is a cure.

The slope of velocity-time curve (i.e. instantaneous acceleration) decreases with time.