Answer :
The force responsible for the downward motion of the ball when it is dropped from rest from the top of a building is the force of gravity. Gravity is a fundamental force of nature that pulls objects towards the center of the Earth. In this scenario, as the ball is released from the top of the building, gravity acts upon it, accelerating it downward.
Here's a breakdown of why the other options are not responsible for the downward motion of the ball:
1. The force of tension: This force is present in a string, rope, or cable that is under tension. In this case, since the ball is dropped freely without any string attached, the force of tension is not relevant.
2. The normal force: The normal force is the force exerted by a surface that supports an object in contact with it. When the ball is dropped, it is not in contact with any surface initially, so the normal force does not play a role in its downward motion.
3. The pushing force: The pushing force would involve an external agent applying a force to the ball in the direction of motion. Since the ball is dropped freely without any external force pushing it, the pushing force is not responsible for its downward motion.
In conclusion, the force of gravity is the primary force responsible for the downward motion of the ball when it is dropped from rest from the top of a building.
