A screw is rotated as shown to provide tension on a cable that passess over a frictionless pulley and pulls on the middle block as shown. The weight of the blocks are W, = 120 lb, W, = 164 lb, W, = 146 lb and the coefficient of static friction for each surface is, µ, = 0.50, µz = 0.43, µz = 0.23. If the bolt with square threads, has a radius, r = 0.32 in, a lead, L = 0.63 in, and a coefficient of friction of µ = 0.41 what is the torque necessary to cause one or both blocks to move? w, Frictionless Pulley w, w, Torque Direction

Structural Analysis
6th Edition
ISBN:9781337630931
Author:KASSIMALI, Aslam.
Publisher:KASSIMALI, Aslam.
Chapter2: Loads On Structures
Section: Chapter Questions
Problem 1P
icon
Related questions
Question
### Problem Description

A screw is rotated as shown to provide tension on a cable that passes over a frictionless pulley and pulls on the middle block as illustrated. The weights of the blocks are as follows:

- \( W_1 = 120 \, \text{lb} \)
- \( W_2 = 164 \, \text{lb} \)
- \( W_3 = 146 \, \text{lb} \)

The coefficients of static friction for each surface are:

- \( \mu_1 = 0.50 \)
- \( \mu_2 = 0.43 \)
- \( \mu_3 = 0.23 \)

The bolt has square threads with the following specifications:

- Radius \( r = 0.32 \, \text{in} \)
- Lead \( L = 0.63 \, \text{in} \)
- Coefficient of friction for the bolt \( \mu = 0.41 \)

**Question:** Determine the torque necessary to cause one or both blocks to move.

### Diagram Explanation

The diagram shows three blocks stacked on top of each other, labeled \( W_1 \), \( W_2 \), and \( W_3 \). Each block is connected with surfaces having different coefficients of static friction (\( \mu_1 \), \( \mu_2 \), and \( \mu_3 \)). A cable runs over a frictionless pulley and is connected to a mechanism with a screw that provides the torque. The mechanism affects the middle block (\( W_2 \)). 

The rotation of the screw in the indicated "Torque Direction" applies tension to the cable.
Transcribed Image Text:### Problem Description A screw is rotated as shown to provide tension on a cable that passes over a frictionless pulley and pulls on the middle block as illustrated. The weights of the blocks are as follows: - \( W_1 = 120 \, \text{lb} \) - \( W_2 = 164 \, \text{lb} \) - \( W_3 = 146 \, \text{lb} \) The coefficients of static friction for each surface are: - \( \mu_1 = 0.50 \) - \( \mu_2 = 0.43 \) - \( \mu_3 = 0.23 \) The bolt has square threads with the following specifications: - Radius \( r = 0.32 \, \text{in} \) - Lead \( L = 0.63 \, \text{in} \) - Coefficient of friction for the bolt \( \mu = 0.41 \) **Question:** Determine the torque necessary to cause one or both blocks to move. ### Diagram Explanation The diagram shows three blocks stacked on top of each other, labeled \( W_1 \), \( W_2 \), and \( W_3 \). Each block is connected with surfaces having different coefficients of static friction (\( \mu_1 \), \( \mu_2 \), and \( \mu_3 \)). A cable runs over a frictionless pulley and is connected to a mechanism with a screw that provides the torque. The mechanism affects the middle block (\( W_2 \)). The rotation of the screw in the indicated "Torque Direction" applies tension to the cable.
Expert Solution
trending now

Trending now

This is a popular solution!

steps

Step by step

Solved in 6 steps with 3 images

Blurred answer
Knowledge Booster
System of units
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, civil-engineering and related others by exploring similar questions and additional content below.
Similar questions
Recommended textbooks for you
Structural Analysis
Structural Analysis
Civil Engineering
ISBN:
9781337630931
Author:
KASSIMALI, Aslam.
Publisher:
Cengage,
Structural Analysis (10th Edition)
Structural Analysis (10th Edition)
Civil Engineering
ISBN:
9780134610672
Author:
Russell C. Hibbeler
Publisher:
PEARSON
Principles of Foundation Engineering (MindTap Cou…
Principles of Foundation Engineering (MindTap Cou…
Civil Engineering
ISBN:
9781337705028
Author:
Braja M. Das, Nagaratnam Sivakugan
Publisher:
Cengage Learning
Fundamentals of Structural Analysis
Fundamentals of Structural Analysis
Civil Engineering
ISBN:
9780073398006
Author:
Kenneth M. Leet Emeritus, Chia-Ming Uang, Joel Lanning
Publisher:
McGraw-Hill Education
Sustainable Energy
Sustainable Energy
Civil Engineering
ISBN:
9781337551663
Author:
DUNLAP, Richard A.
Publisher:
Cengage,
Traffic and Highway Engineering
Traffic and Highway Engineering
Civil Engineering
ISBN:
9781305156241
Author:
Garber, Nicholas J.
Publisher:
Cengage Learning