Is Tension Constant in a Massless String?

Click For Summary
SUMMARY

Tension in a massless string remains constant throughout its length due to the absence of mass. When analyzing a segment of the string with mass Δm, the forces acting on it are T1 to the right and T2 to the left. The force equation T2 - T1 = Δma indicates that since Δm equals zero, T2 must equal T1. This confirms that tension is uniform across the entire length of the massless string.

PREREQUISITES
  • Understanding of Newton's laws of motion
  • Basic knowledge of force equations
  • Familiarity with concepts of mass and acceleration
  • Comprehension of tension in physics
NEXT STEPS
  • Study the implications of massless objects in physics
  • Explore tension in non-massless strings and its variations
  • Learn about the role of acceleration in force equations
  • Investigate real-world applications of tension in engineering
USEFUL FOR

Physics students, educators, and anyone interested in understanding the principles of tension and force in mechanics.

andyrk
Messages
658
Reaction score
5
Why is tension in a massless string same throughout its length?
 
Physics news on Phys.org
andyrk said:
Why is tension in a massless string same throughout its length?

Consider a massless string being pulled horizontally towards right.

The forces acting on a tiny bit of the string having mass Δm will be T1 towards right and T2 towards left.The force equation will be T2-T1=Δma where 'a' is the acceleration of the tiny bit of the string .Now since Δm=0 ∴ T2=T1 i.e tension on either side of any arbitrary mass of the string is zero.In other words tension throughout the string is constant.
 

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?
View full post »

Similar threads

Does a massless string cause a normal force when attached to a wall?
  • · Replies 2 ·
Replies
2
Views
1K
The acceleration of a massless pulley in a double Atwood machine
  • · Replies 2 ·
Replies
2
Views
2K
2 pullies and 3 masses -Tension
  • · Replies 18 ·
Replies
18
Views
4K
Ideal Vs Real Mass Pulley system
  • · Replies 10 ·
Replies
10
Views
5K
Force pulling on a string at an angle with a block at the other end
  • · Replies 2 ·
Replies
2
Views
1K
How can I pluck strings (with changing length) with constant energy?
  • · Replies 1 ·
Replies
1
Views
1K
Rocket + Connected Body Dynamics problem
  • · Replies 47 ·
2
Replies
47
Views
3K
Time it Takes for a Transverse Pulse to Travel a Distance "L" Up a Cable Against Gravity?
  • · Replies 13 ·
Replies
13
Views
2K
Tension in a string connecting two blocks having equal and opposite velocities
  • · Replies 21 ·
Replies
21
Views
889
Tension in a string in circular motion
  • · Replies 15 ·
Replies
15
Views
6K