Answer:
No, the sinking of a stone when dropped into water does not happen due to the absence of upthrust. In fact, the concept of upthrust (or buoyant force) plays a crucial role in determining whether an object sinks or floats in a fluid.
When a stone is dropped into water, several forces act upon it:
1. **Weight (gravitational force)**: This is the force pulling the stone downwards due to gravity.
2. **Upthrust (buoyant force)**: This is the upward force exerted by the water on the stone, which opposes the weight of the stone.
Whether the stone sinks or floats depends on the relative magnitudes of these forces:
- If the weight of the stone is greater than the upthrust, the stone will sink. This happens because the downward gravitational force (weight) is stronger than the upward buoyant force.
- If the weight of the stone is less than or equal to the upthrust, the stone will float or remain at the water surface. In this case, the buoyant force is strong enough to support the weight of the stone.
Therefore, the sinking of a stone into water is primarily due to the gravitational force (weight) being greater than the buoyant force (upthrust), causing the stone to move downwards through the water until it reaches a point where its density and the water density are balanced.
