Answer:
B) unbalanced forces
Step-by-step explanation:
The question you've posed is about understanding why objects move, a fundamental concept in physics. To address this, we need to consider the principles that govern motion. Let's talk about each option:
- A) Inertia: Inertia is the tendency of an object to resist changes in its state of motion. It explains why an object at rest remains at rest or an object in motion stays in motion with the same speed and in the same direction unless acted upon by an unbalanced force. However, inertia itself does not cause motion; it's more about resistance to change in motion.
- B) Unbalanced Forces: This is the key to understanding motion. According to Newton's First Law of Motion, an object will only change its state of motion (i.e., start moving, change direction, or stop) if it is acted upon by an unbalanced force. Unbalanced forces are not equal and opposite, so they result in a net force on an object causing it to accelerate.
- C) Balanced Forces: When forces are balanced, they are equal in magnitude and opposite in direction, canceling each other out. As a result, balanced forces do not change the motion of an object. An object at rest will stay at rest, and an object in motion will continue moving at constant velocity under balanced forces.
- D) None of the Above: This option is incorrect since one of the above options is correct.
Thus, objects move because of unbalanced forces acting on them. So, this makes (B) the correct choice.