An unbalanced force can cause an object to:

A. Change the direction of its velocity

B. Change the magnitude of its velocity

C. Remain motionless

D. Remain moving with its current speed and direction

It'll speed up in the direction it's being pushed unbalanced. Or, it could slow down if applied the right amount of unbalanced power. And finally if the unbalanced push is pushed it could change the direction of it's current motion it was traveling.