Why Does a Sphere Reach Terminal Velocity if Buoyant Force Exceeds Weight?

In summary, the conversation discusses the concept of terminal velocity and the role of different forces in determining the direction of motion. The speaker proposes a solution to a problem involving determining the weight, buoyant force, and drag force of an object. However, they are confused by the idea of the drag force acting downwards when the buoyant force is greater than the weight. They then correct themselves and state that the sphere is actually going up instead of down, as the buoyant force is larger than the weight.
  • #1
Est120
54
3
Homework Statement
determine the drag force
Relevant Equations
Archimedes principle formula, weight formula
in my head this is just a silly problem in which i need to determine the ↓ force (weight) and the ↑force (archimedes bouyant force) and then the difference must be the drag force ↑ (the force that involves velocity) but i can't get any sense out of this answer
how is possible for the sphere to reach terminal velocity (and thus keep falling) if the bouyant force is greater in magnitude than the weight?
how is the drag force acting downwards (in the direction of motion) ? this doesn't make any sense to me
1617844843207.png
 

Attachments

  • Captura.JPG
    Captura.JPG
    35.7 KB · Views: 116
Physics news on Phys.org
  • #2
i think the sphere must be going up instead of down so this actually makes sense
 
  • #3
It Is going up. The buoyant force Is larger than the Wright.
 

FAQ: Why Does a Sphere Reach Terminal Velocity if Buoyant Force Exceeds Weight?

1. What is the motion of a sphere in a liquid?

The motion of a sphere in a liquid is a result of the interaction between the sphere and the surrounding liquid. It can be affected by various factors such as the density of the liquid, the size and shape of the sphere, and the viscosity of the liquid.

2. How does the density of the liquid affect the motion of a sphere?

The density of the liquid affects the motion of a sphere by creating a buoyant force that opposes the weight of the sphere. This buoyant force can either slow down or speed up the motion of the sphere depending on the density of the liquid and the density of the sphere.

3. What is the role of viscosity in the motion of a sphere in a liquid?

Viscosity is the measure of a liquid's resistance to flow. In the motion of a sphere in a liquid, viscosity plays a crucial role in determining the speed and direction of the sphere's motion. A more viscous liquid will result in a slower and more turbulent motion of the sphere, while a less viscous liquid will allow for a faster and smoother motion.

4. How does the size and shape of the sphere affect its motion in a liquid?

The size and shape of the sphere can greatly impact its motion in a liquid. A larger sphere will experience more resistance and therefore have a slower motion compared to a smaller sphere. The shape of the sphere can also affect its motion, with more streamlined shapes experiencing less resistance and having a faster motion.

5. What is the significance of the Reynolds number in the motion of a sphere in a liquid?

The Reynolds number is a dimensionless quantity that represents the ratio of inertial forces to viscous forces in a fluid flow. In the motion of a sphere in a liquid, the Reynolds number determines whether the flow is laminar or turbulent. A low Reynolds number indicates a laminar flow, while a high Reynolds number indicates a turbulent flow. This can greatly affect the motion of the sphere and the forces acting upon it.

Similar threads

Drag force on a descending sphere
Replies
6
Views
1K
Motion of a Parachuter (Terminal Velocity, Time of Flight, Distance)
Replies
10
Views
613
How does the velocity of a ball change without buoyant force acting on it?
Replies
17
Views
1K
How do I find the terminal speed of a body in water?
Replies
13
Views
4K
Effect of density on downward rolling spheres
Replies
14
Views
3K
Terminal Velocity: How does one explain why the squirrel gets undamaged?
Replies
13
Views
22K
An experiment from which you can calculate terminal velocity
Replies
6
Views
7K
Question: How does mass affect terminal velocity when a drag force is present?
Replies
2
Views
3K
Vertical circle in a pendulum ride -- tension force acting on the gondola
Replies
7
Views
2K
Calculate Vertical Displacement with Drag Force Equation | Physics Homework
Replies
13
Views
2K

Hot Threads

Recent Insights

Back
Top