Question

Velocity of a body is negative while going upwards or downwards?

Answer 1

When you project an object upward and release it at its initial velocity, it is moving in the opposite direction of the force of gravity. Thus the initial velocity is negative. The velocity of the object is also negative on the way up but positive on the way down.

Note: The convention we use is that upward velocities are negative and downward velocities are positive. Also, displacements above the starting point are negative and those below the starting point are positive.

Some textbooks consider up as positive and down as negative. You need to be aware of what convention is being used when working from a book.