gravitey
An unbalanced force can: change the speed an object moves at change the direction an object is moving cause an object to start/stop moving
I think this question is not phrased very well. Any force can change objects velocity (speed+direction). If fact that is the definition of the force - F=ma any force, by definition itself, can change objects velocity. Maybe you meant what force can change objects direction of motion? In that case - any force that has a different direction (not the same as direction of motion) Any force can change an object's motion.
A Force.
A basic physics answer for this is that a net force (or unbalanced force) will cause an object to accelerate, that is, cause the object to change its speed and/or direction.
An unbalanced force will cause acceleration in the direction of the force.
A force is a push or pull that can cause an object to move, stop, or change speed or direction.
Objects in motion continuously change position.To change direction, a force needs to act upon them.
gravitey
Pressure can cause objects to change shape
Forces cause motion or the change in motion.
A basic physics answer for this is that a net force (or unbalanced force) will cause an object to accelerate, that is, cause the object to change its speed and/or direction.