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

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SUMMARY

The discussion centers on the physics of a sphere reaching terminal velocity when the buoyant force exceeds its weight. Participants clarify that while the buoyant force acts upwards, the drag force, which opposes the motion, increases with velocity. When the sphere reaches terminal velocity, the net forces acting on it (weight, buoyant force, and drag) balance out, allowing it to continue falling at a constant speed despite the buoyant force being greater than its weight. This phenomenon illustrates the complex interplay of forces in fluid dynamics.

PREREQUISITES
  • Understanding of Newton's laws of motion
  • Familiarity with Archimedes' principle
  • Basic knowledge of drag force and its relationship with velocity
  • Concept of terminal velocity in fluid dynamics
NEXT STEPS
  • Study the principles of fluid dynamics and how forces interact in a fluid
  • Research the mathematical formulation of drag force and its dependence on velocity
  • Explore case studies of terminal velocity in various shapes and sizes
  • Learn about the applications of buoyancy in engineering and design
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Physics students, educators, and anyone interested in understanding the dynamics of objects in fluids, particularly in relation to buoyancy and terminal velocity.

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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 buoyant 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 buoyant 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
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i think the sphere must be going up instead of down so this actually makes sense
 
It Is going up. The buoyant force Is larger than the Wright.
 

Thread 'Magnitude of buoyant force in fluids of different densities'

The book claims the answer is that all the magnitudes are the same because "the gravitational force on the penguin is the same". I'm having trouble understanding this. I thought the buoyant force was equal to the weight of the fluid displaced. Weight depends on mass which depends on density. Therefore, due to the differing densities the buoyant force will be different in each case? Is this incorrect?
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