The Work - Energy Theorem in a pulley?

Click For Summary
SUMMARY

The discussion focuses on applying the Work-Energy Theorem to a pulley system involving an 8.00-kg block and a 6.00-kg block. The system is frictionless with a coefficient of kinetic friction of \mu_k=0.250 between the block and the tabletop. The objective is to calculate the speed of the 6.00-kg block after it descends 1.50 m. Key calculations involve determining the loss in potential energy (PE), the gain in kinetic energy (KE), and the work done against friction.

PREREQUISITES
  • Understanding of the Work-Energy Theorem
  • Knowledge of potential and kinetic energy calculations
  • Familiarity with friction coefficients and their impact on motion
  • Basic algebra for solving equations involving energy
NEXT STEPS
  • Calculate the loss in potential energy for the 6.00-kg block using PE = mgh
  • Determine the gain in kinetic energy for the 6.00-kg block using KE = (1/2)mv^2
  • Analyze the work done against friction using W = F_friction * distance
  • Explore the implications of varying the coefficient of kinetic friction on the system's dynamics
USEFUL FOR

Physics students, educators, and anyone interested in understanding the dynamics of pulley systems and energy conservation principles.

erik-the-red
Messages
88
Reaction score
1
Consider the system shown in the figure. The rope and pulley have negligible mass, and the pulley is frictionless. The coefficient of kinetic friction between the 8.00-kg block and the tabletop is [tex]\mu_k=0.250.[/tex] The blocks are released from rest.

Use energy methods to calculate the speed of the 6.00-kg block after it has descended 1.50 m.

[tex]\Delta * K[/tex] = [tex](1/2)(m)(v_f^2 - v_i^2)[/tex]

But, it was at rest, so [tex](1/2)(m)(v_f^2)[/tex] is what matters.

What do I do next?
 

Attachments

  • Imajj.jpg
    Imajj.jpg
    7 KB · Views: 753
Physics news on Phys.org
You will have a loss in PE balanced by a gain in KE and work done.

What is it that loses PE, and by how much ?

What are the gains in KE and by how much ?

What work is done and how much ?
 
Last edited:

Similar threads

  • · Replies 9 ·
Replies
9
Views
4K
  • · Replies 5 ·
Replies
5
Views
6K
Replies
13
Views
4K
Replies
24
Views
4K
  • · Replies 4 ·
Replies
4
Views
4K
  • · Replies 8 ·
Replies
8
Views
4K
  • · Replies 1 ·
Replies
1
Views
3K
  • · Replies 3 ·
Replies
3
Views
3K
  • · Replies 6 ·
Replies
6
Views
4K
  • · Replies 9 ·
Replies
9
Views
2K