# Review of equations of uniformly accelerated motion (Chapter 3.5)

In school physics we have studied some useful equations for objects moving at constant acceleration.

Suppose an object is moving with uniform acceleration a along a straight line. If is initial velocity is v, and final velocity after a time interval t is v1. Let the distance covered during this interval be S the we have

These equations are useful only for linear motion with uniform acceleration. When the object moves along a straight line, the direction of motion does not change. In this case all the vectors can be manipulated like scalars. In such problems, the direction of initial velocity is taken as positive. A negative sign is assigned to quantities where direction is opposite to that of initial velocity.

The equation for uniformly accelerated motion can also be applied to free fall motion of the objects by replacing a by g.

**Do You know?**

How the displacement of a vertically thrown ball varies with time?

How the velocity of a vertically thrown ball varies with time? Velocity is upwards positive.

**Do You Know?**

At the surface of the earth, in situations where air friction is negligible, objects fall with the same acceleration regardless of their weights.