Speed of ball changed by lengthening string

Click For Summary
SUMMARY

The discussion centers on the physics of a ball with a mass of 0.18 kg being whirled in a horizontal circle at a speed of 4.5 m/s on a massless string. When the string length is increased from 75 cm to 1.5 m, the speed of the ball changes due to the principles of angular momentum conservation. The relevant formula applied here is the conservation of angular momentum, which states that if no external torque acts on the system, the angular momentum remains constant.

PREREQUISITES
  • Understanding of angular momentum
  • Familiarity with circular motion concepts
  • Knowledge of mass and velocity relationships
  • Basic grasp of torque and its effects
NEXT STEPS
  • Study the conservation of angular momentum in detail
  • Explore the effects of string length on circular motion dynamics
  • Learn about the relationship between radius and tangential speed
  • Investigate real-world applications of circular motion principles
USEFUL FOR

Physics students, educators, and anyone interested in understanding the dynamics of circular motion and angular momentum conservation.

fattydq
Messages
79
Reaction score
0
A ball of mass 0.18 kg is whirled in a horizontal circle at the end of a massless string 75 cm long at a speed of 4.5 m/s. If the string is lengthened to 1.5 m while the ball is being twirled, then the speed of the ball will now be...

What law or formula applies to this question?
 
Physics news on Phys.org
I think you're supposed to assume that external torque is 0, so the conservation law is...
 

Similar threads

Replies
1
Views
2K
  • · Replies 9 ·
Replies
9
Views
2K
  • · Replies 10 ·
Replies
10
Views
3K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 16 ·
Replies
16
Views
3K
  • · Replies 5 ·
Replies
5
Views
2K
Replies
4
Views
2K
  • · Replies 7 ·
Replies
7
Views
10K
  • · Replies 9 ·
Replies
9
Views
4K
  • · Replies 4 ·
Replies
4
Views
1K