Find tension of string in a pendulum

Click For Summary
SUMMARY

The discussion focuses on calculating the tension in a pendulum string, given a length of 0.615 m, a bob mass of 1.37 kg, and a bob velocity of 1.40 m/s at an angle of 14.1° from the vertical. Participants are tasked with finding the tangential and radial acceleration components, as well as the tension in the string using Newton's second law. The initial attempts yielded incorrect results for tangential acceleration (6.54 m/s² and 6.74 m/s²) and tension (13.02 N), indicating a need for a more precise application of force analysis in both radial and tangential directions.

PREREQUISITES
  • Understanding of Newton's second law (F=MA)
  • Knowledge of free body diagrams (FBD)
  • Familiarity with components of gravitational force
  • Basic principles of circular motion
NEXT STEPS
  • Review the calculation of tangential and radial acceleration in pendulum motion
  • Study the decomposition of forces in a free body diagram
  • Learn about centripetal force and its relation to tension in pendulum systems
  • Explore examples of pendulum dynamics to reinforce understanding of the concepts
USEFUL FOR

Students studying physics, particularly those focusing on mechanics and pendulum motion, as well as educators seeking to clarify concepts related to forces and accelerations in pendulum systems.

Jtappan
Messages
95
Reaction score
0

Homework Statement



A pendulum is 0.615 m long and the bob has a mass of 1.37 kg. When the string makes an angle of =14.1° with the vertical, the bob is moving at 1.40 m/s. Find the tangential and radial acceleration components and the tension in the string. [Hint: Draw an FBD for the bob. Choose the x-axis to be tangential to the motion of the bob and the y-axis to be radial. Apply Newton's second law.]
at = _____m/s2
ar = _____ m/s2
T = _______ N

Homework Equations



F=MA

The Attempt at a Solution



I have tried breaking up the forced using the FBD but I cannot get the right answer for any of them. I have no idea what I am doing wrong. For the tangential acceleration i got: 6.54 and 6.74 doing it two different ways. For tension I got 13.02 N and those are still not correct...
 
Physics news on Phys.org
In the y (radial) direction there is T and a component of gravity.
In the x (tangential) direction, there is only the other component of gravity.

So figure out Fnet in the tangential direction then Fnet in the radial direction.
 

Similar threads

  • · Replies 20 ·
Replies
20
Views
2K
  • · Replies 12 ·
Replies
12
Views
2K
  • · Replies 11 ·
Replies
11
Views
6K
  • · Replies 4 ·
Replies
4
Views
4K
  • · Replies 2 ·
Replies
2
Views
7K
  • · Replies 3 ·
Replies
3
Views
3K
Replies
1
Views
4K
  • · Replies 8 ·
Replies
8
Views
2K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 5 ·
Replies
5
Views
3K