Find the total work done on 20.0N block

Click For Summary

Homework Help Overview

The problem involves two blocks connected by a string over a pulley, with one block weighing 20.0N and the other 12.0N. The blocks move different distances, and the task is to calculate the total work done on each block under various friction conditions.

Discussion Character

  • Exploratory, Assumption checking

Approaches and Questions Raised

  • Participants discuss the calculation of work done on each block, questioning the role of friction and the forces acting on the blocks. There is an exploration of why initial calculations resulted in zero work done.

Discussion Status

Some participants have provided guidance by asking about the forces acting on each block, while others reflect on their attempts to solve the problem and express uncertainty about their calculations. There is a mix of exploration and clarification occurring.

Contextual Notes

Participants are navigating different scenarios involving friction, with some indicating that their initial assumptions may have led to incorrect conclusions. The discussion highlights the importance of understanding the forces at play in the system.

bharp24
Messages
14
Reaction score
0
Two blocks are connected by a very light string passing over a massless and frictionless pulley. The 20.0N block moves 75.0cm to the right and the 12.0N block moves 75.0cm downward.

Find the total work done on 20.0N block if there is no friction between the table and the 20.0N block.

Find the total work done on 12.0N block if there is no friction between the table and the 20.0N block.

Find the total work done on 20.0N block if static friction=0.500 and kinetic friction=0.325 between the table and the 20.0- block.

Find the total work done on 12.0N block if static friction=.500 and kinetic friction=.325between the table and the 20.0N block.

For the first two, I got total work done for both individual boxes to be 0J, but this is not correct somehow. I cannot really go on with the third and fourth scenarios until I get the first two. Can someone please help??
 
Physics news on Phys.org
bharp24 said:
For the first two, I got total work done for both individual boxes to be 0J, but this is not correct somehow.
How did you determine this? What forces act on each block?
 
i think i went ahead and added a friction force into the first 2, which zeros them out. i still get a wrong answer though when I leave the friction out. any suggestions on how to complete this problem?
 
Start by answering my question: What forces act on each block?
 
i tried it again and got it right. thanks for trying to help me out!
 

Similar threads

Confused conceptually about work done with pulleys
  • · Replies 8 ·
Replies
8
Views
3K
Finding the work done by a block
  • · Replies 4 ·
Replies
4
Views
3K
Find work given a pulley and two weights
  • · Replies 6 ·
Replies
6
Views
5K
Why is the work done double its expected value? (conveyer belt)
  • · Replies 58 ·
2
Replies
58
Views
6K
Work Done by Gravity and Tension in a Pulley System
  • · Replies 3 ·
Replies
3
Views
3K
Work done by friction on a two-block system
  • · Replies 7 ·
Replies
7
Views
3K
Calculating Work in a Pulley System
  • · Replies 11 ·
Replies
11
Views
15K
What is the kinetic energy of the block when it is moved 2cm.
  • · Replies 3 ·
Replies
3
Views
3K
What is the work done on cart by the string?
  • · Replies 1 ·
Replies
1
Views
2K
Finding the Coefficient of Friction in a Spring-Block Incline System
  • · Replies 2 ·
Replies
2
Views
2K