Velocity of Sphere Falling from Rest in Oil-Filled Beaker

Click For Summary
SUMMARY

The velocity of a sphere falling from rest in a tall beaker filled with oil is influenced by two primary forces: gravity and fluid resistance. Initially, when the sphere's velocity is zero, only the gravitational force acts on it, as fluid resistance is proportional to velocity and thus zero at that moment. As the sphere accelerates downward, fluid resistance increases until it balances with gravitational force, resulting in a terminal velocity where acceleration approaches zero. This dynamic illustrates the relationship between gravitational force and fluid dynamics in a viscous medium.

PREREQUISITES
  • Understanding of Newton's laws of motion
  • Basic principles of fluid dynamics
  • Knowledge of terminal velocity concepts
  • Familiarity with forces acting on objects in fluids
NEXT STEPS
  • Study the concept of terminal velocity in different fluids
  • Explore the equations governing fluid resistance, such as Stokes' law
  • Investigate the effects of varying fluid densities on falling objects
  • Learn about the role of viscosity in fluid dynamics
USEFUL FOR

Physics students, engineers, and anyone interested in fluid dynamics and the behavior of objects in viscous environments will benefit from this discussion.

Angela Liang
Messages
36
Reaction score
1
Hi! I'm thinking how would the velocity of a sphere change if it falls from rest in a tall beaker full of oil. I know that the direction of acceleration is upwards, and the acceleration should be decreasing at a decreasing rate. But how would the velocity change if the velocity is initially zero and falling downwards, meaning the acceleration has to slow it down. How does it slow down when the velocity is zero? And how can it be for the ball not to have velocity when it falls? Thanks.
 
Physics news on Phys.org
Angela Liang said:
Hi! I'm thinking how would the velocity of a sphere change if it falls from rest in a tall beaker full of oil. I know that the direction of acceleration is upwards, and the acceleration should be decreasing at a decreasing rate. But how would the velocity change if the velocity is initially zero and falling downwards, meaning the acceleration has to slow it down. How does it slow down when the velocity is zero? And how can it be for the ball not to have velocity when it falls? Thanks.
The force of gravity on the sphere will be a constant. The force against the fluid will be a function of its velocity through the fluid.
At zero velocity, the force from the fluid will be zero and only gravity will be acting on it. These two forces would balance out at a "terminal velocity". So, as the sphere approaches that velocity, the acceleration will approach zero.
 
.Scott said:
The force of gravity on the sphere will be a constant. The force against the fluid will be a function of its velocity through the fluid.
At zero velocity, the force from the fluid will be zero and only gravity will be acting on it. These two forces would balance out at a "terminal velocity". So, as the sphere approaches that velocity, the acceleration will approach zero.
Ok. Thank you very much!
 

Similar threads

High School Time to fall from 200 miles
  • · Replies 8 ·
Replies
8
Views
2K
High School Understanding Galileo's Theory of Acceleration
  • · Replies 8 ·
Replies
8
Views
2K
Undergrad Help Needed with Tracker Physics Program Measuring Acceleration
  • · Replies 10 ·
Replies
10
Views
2K
Undergrad A rod that falls while rotating from the end of a table
  • · Replies 2 ·
Replies
2
Views
2K
High School Rolling of non-deforming sphere on a non-deforming rough surface?
  • · Replies 4 ·
Replies
4
Views
2K
High School Friction on pure rolling non deforming sphere?
  • · Replies 3 ·
Replies
3
Views
2K
Graduate Is Velocity Increasing Below the X-Axis?
  • · Replies 17 ·
Replies
17
Views
2K
High School What will be the ball's velocity after a perfectly elastic collision?
  • · Replies 4 ·
Replies
4
Views
1K
High School How will object's velocity change when a frictional force increases?
  • · Replies 16 ·
Replies
16
Views
2K
High School Zero acceleration = zero net force?
  • · Replies 33 ·
2
Replies
33
Views
3K