Why would the initial velocity of somethng NOT be zero?

Question

I am guessing it has something to do forces but im not sure. 

Answer 1

Consider an artillery shell emerging from a canon after being fired.  At the time it emerges from the canon, it has a non-zero velocity.  You can set your clock so that the time the shell emerges from the cannon is the t=0 time.  Then you have a non-zero initial velocity.  When you solve projectile motion problems, the kinematic equations have non-zero initial velocities.

 

Answer 2

Just to complement these fine answers with one stated slightly differently:  you are allowed, in physics problems, to select an interval of interest whenever you want (the t = 0 that Arturo mentioned).  You don't have to start with everything at rest.  You can set the starting time whenever you want.  If you choose to start looking when something is already moving, that object will have an initial velocity that is not zero.

 

For projectiles, as Arturo mentioned, we tend to start looking at an object after it has been launched, and already attained some speed, so it has a non-zero initial velocity.

Answer 3

Well if an object starts from rest then it's initial velocity would be zero however if it is already in motion then it does have an initial velocity of greater than zero.