The answer is:
3) a hockey puck moving at constant velocity across ice.
The explanation:
when the Balanced forces do not cause a change in motion. When balanced forces act on an object at rest, the object will not move. If you push against a wall, the wall pushes back with an equal but opposite force. Neither you nor the wall will move. Forces that cause a change in the motion of an object are unbalanced forces.
- A force which is not opposed by a force of equal magnitude and acting in the exact opposite direction hence leading to the motion of the object is called an unbalanced force.
- The forces which speed up slow down the objects or makes them change their direction are called Unbalanced forces.
and the phase which satisfy this definition is (3)