Suppose an object is released from rest in the middle of a container of viscous
ID: 250308 • Letter: S
Question
Suppose an object is released from rest in the middle of a container of viscous fluid. The density of the object is less than the density of the fluid. Which one of the following statements is correct?
The object will remain at rest because the resistive force of the fluid will be equal and opposite to the buoyant force of the fluid on the object.
The object will move upward, eventually reaching a constant upward terminal speed.
The object will move downward, eventually reaching a constant downward terminal speed.
Explanation / Answer
The object will move upward, eventually reaching a constant upward terminal speed.
The density of the object is less than that of the liquid, it subject a buoyant force that is larger than its weight, so it subject a upward net force and start to accelerate.
As it start to move the resistive force of the fluid start to kick in, which is increases as V increases, until it increase to balance the initial net force, then it move in upward terminal velocity