Which of the following may happen when an object receives unbalanced forces?

Options

A. The object changes direction.
B. The object changes speed.
C. The object starts to move.
D. All of the above.

Answer

### Step-by-Step Solution:

1. **Understanding Unbalanced Forces**:
- When an object experiences unbalanced forces, it means that the total or net force acting on the object is not zero. This occurs when the forces acting on the object do not cancel each other out.

2. **Effect on Motion**:
- An unbalanced force will cause the object to move. If the object was at rest, it will start moving in the direction of the net force. If it was already in motion, the unbalanced force can change its speed or direction.

3. **Change in Speed**:
- The application of an unbalanced force can lead to acceleration, which is a change in speed. If the force is applied in the same direction as the object's motion, it will speed up. Conversely, if the force is applied in the opposite direction, it will slow down.

4. **Change in Direction**:
- An unbalanced force can also change the direction of an object’s motion. For example, if two forces are applied at angles to each other, the object will move in the direction of the resultant force, which can be determined using vector addition.

5. **Conclusion**:
- Therefore, when an object receives unbalanced forces, it can start moving, change its speed, or change its direction of motion.

### Summary of Possible Outcomes:
- The object may start moving if it was at rest.
- The object may change its speed if it was already in motion.
- The object may change its direction of motion depending on the direction of the net force.