The block will balance the forces. The forces will reverse direction. The mass of the block will change. The position of the block will change.
I gave my students this multiple choice question: Two forces act in opposite directions on a wood block. What will happen if the forces are unbalanced?

Only one answer is correct among these 4 choices:
- The block will balance the forces.
- The forces will reverse direction.
- The mass of the block will change.
- The position of the block will change.

Could you tell me which one is correct?

The position of the block will change.