Physics Demo: Why Does 20 Pound Ball Fall Differently?

  • Context: Undergrad 
  • Thread starter Thread starter drew102
  • Start date Start date
  • Tags Tags
    Physics
Click For Summary
SUMMARY

The discussion centers on a physics demonstration involving a 20-pound ball suspended by two strings. When a rod is yanked quickly through the bottom loop, the bottom string breaks, while a slow push causes the top string to snap, resulting in the ball falling. This phenomenon is explained by impulse-momentum equations, specifically FΔT, highlighting the difference in tension dynamics between rapid and gradual force application. The key takeaway is that the rate of force application significantly influences which string fails first.

PREREQUISITES
  • Understanding of impulse-momentum equations (FΔT)
  • Basic knowledge of tension in strings and forces
  • Familiarity with Newton's laws of motion
  • Concept of force application rates and their effects
NEXT STEPS
  • Research the principles of impulse-momentum in physics
  • Explore Newton's laws of motion in greater detail
  • Study tension dynamics in various physical systems
  • Investigate real-world applications of force application rates
USEFUL FOR

This discussion is beneficial for physics students, educators demonstrating fundamental concepts, and anyone interested in the practical applications of mechanics and force dynamics.

drew102
Messages
1
Reaction score
0
Ok so here is the situation: There is a 20 pound ball hanging from a string in a loop. below the ball, there is another identical string attached loosely in a loop. So here is what happens. A person puts a rod through the bottom loop and yanks really hard and the result is the bottom string breaks. However if you put the rod through the same loop at the bottom and then push really slowly the top sting snaps and the ball falls. Why does this happen?
 
Physics news on Phys.org
My physics teacher did this demonstration with my class as well. It has to do with the impulse-momentum equations, I think ([itex]F\DeltaT[/itex]).

When the force is slowly increased, the top string obviously has more tension (whatever force is being applied plus the weight of the ball). When the force is increased very quickly, a large force is applied to a specific point on the ball and the tension does not have time to travel to the top?

...
...Maybe. I thought I knew, but maybe I don't. It's been so long since school!
 

Similar threads

Undergrad Why Does Dropping a Ball into a Well Result in Different Energy Sums?
  • · Replies 10 ·
Replies
10
Views
4K
Undergrad Falling Feather and ball in vacuum
  • · Replies 13 ·
Replies
13
Views
3K
Undergrad Why do objects fall at the same speed in free fall?
  • · Replies 30 ·
2
Replies
30
Views
6K
Undergrad What is the difference between elastic and inelastic collisions?
  • · Replies 1 ·
Replies
1
Views
2K
Undergrad Momentum, Inertia, and Deflection
  • · Replies 2 ·
Replies
2
Views
3K
Graduate Why does the Split-finger baseball pitch break?
  • · Replies 8 ·
Replies
8
Views
8K
Undergrad How Does the Rain Frame Affect Perception of a Ball Falling Off a Cliff?
  • · Replies 3 ·
Replies
3
Views
2K
Undergrad Why Does Tugging Speed Affect the Outcome in a Two-String Physics Problem?
  • · Replies 2 ·
Replies
2
Views
2K
Undergrad Why the Frequency of Light Does Not Change Through a Medium
  • · Replies 9 ·
Replies
9
Views
6K
High School Why Does One Side of a Belt Fall When Hung Unevenly?
  • · Replies 3 ·
Replies
3
Views
2K