/*! This file is auto-generated */ .wp-block-button__link{color:#fff;background-color:#32373c;border-radius:9999px;box-shadow:none;text-decoration:none;padding:calc(.667em + 2px) calc(1.333em + 2px);font-size:1.125em}.wp-block-file__button{background:#32373c;color:#fff;text-decoration:none} Q9-5Q A ground retaining wall is shown... [FREE SOLUTION] | 91影视

91影视

Log out

Learning Materials

Features

Discover

Chapter 9: Q9-5Q (page 230)

A ground retaining wall is shown in Fig. 9鈥�36a. The ground, particularly when wet, can exert a significant force F on the wall. (a) What force produces the torque to keep the wall upright? (b) Explain why the retaining wall in Fig. 9鈥�36b would be much less likely to overturn than that in Fig. 9鈥�36a.

Short Answer

Expert verified

a) Gravitational force produces the torque to keep the wall upright.

(b) Due to the higher mass of the second wall, the torque produced by gravity (to hold the wall upright) will be greater for the second wall.

Step by step solution

01

Understanding torque

The term torque may be defined as the quantity that estimates the capacity of a force to twist an object about some fulcrum. It is also referred to as the moment of force.

02

Force that produces the torque

In the case of (a), if the ground exerts a force on the wall, the gravitational force acting through the center of mass of the wall will produce enough torque on the wall to keep it upright.

03

Explanation for why the retaining wall in Fig. 9–36b would be much less likely to overturn than that in Fig. 9–36a

(b)

In the case of (b), the wall's mass is large, and the torque through the center of mass will be sufficient enough to keep the wall upright.

The ground above the extended part of the wall will provide a clockwise torque on the wall. Moreover, the center of mass of the total wall is to the right of the rotation point of the wall, and the gravitational force acting through the center of mass of the wall exerts a clockwise torque.

Thus, in case (b), the wall is less likely to overturn.

Unlock Step-by-Step Solutions & Ace Your Exams!

  • Full Textbook Solutions

    Get detailed explanations and key concepts

  • Unlimited Al creation

    Al flashcards, explanations, exams and more...

  • Ads-free access

    To over 500 millions flashcards

  • Money-back guarantee

    We refund you if you fail your exam.

Over 30 million students worldwide already upgrade their learning with 91影视!

One App. One Place for Learning.

All the tools & learning materials you need for study success - in one app.

Get started for free

Most popular questions from this chapter

Why is it not possible to sit upright in a chair and rise to your feet without first leaning forward?

The force required to pull the cork out of the top of a wine bottle is in the range of 200 to 400 N. What range of force F is required to open a wine bottle with the bottle opener shown in Fig. 9鈥�55?


When a wood shelf of mass 6.6 kg is fastened inside a slot in a vertical support as shown in Fig. 9鈥�92, the support exerts a torque on the shelf. (a) Draw a free-body diagram for the shelf, assuming three vertical forces (two exerted by the support slot鈥攅xplain why). Then calculate (b) the magnitudes of the three forces and (c) the torque exerted by the support (about the left end of the shelf).

(II) The two trees in Fig. 9鈥�51 are 6.6 m apart. A backpacker is trying to lift his pack out of the reach of bears. Calculate the magnitude of the force\(\vec F\)that he must exert downward to hold a 19-kg backpack so that the rope sags at its midpoint by (a) 1.5 m, (b) 0.15 m.


In a mountain-climbing technique called the 鈥淭yrolean traverse,鈥� a rope is anchored on both ends (to rocks or strong trees) across a deep chasm, and then a climber traverses the rope while attached by a sling as in Fig. 9鈥�91. This technique generates tremendous forces in the rope and anchors, so a basic understanding of physics is crucial for safety. A typical climbing rope can undergo a tension force of perhaps 29 kN before breaking, and a 鈥渟afety factor鈥� of 10 is usually recommended. The length of rope used in the Tyrolean traverse must allow for some 鈥渟ag鈥� to remain in the recommended safety range. Consider a 75-kg climber at the center of a Tyrolean traverse, spanning a 25-m chasm. (a) To be within its recommended safety range, what minimum distance x must the rope sag? (b) If the Tyrolean traverse is set up incorrectly so that the rope sags by only one-fourth the distance found in (a), determine the tension in the rope. Ignore stretching of the rope. Will the rope break?
See all solutions

Recommended explanations on Physics Textbooks

Thermodynamics

Read Explanation

Energy Physics

Read Explanation

Translational Dynamics

Read Explanation

Physics of Motion

Read Explanation

Dynamics

Read Explanation

Turning Points in Physics

Read Explanation
View all explanations

What do you think about this solution?

We value your feedback to improve our textbook solutions.

Study anywhere. Anytime. Across all devices.