Exercise 8.3 Hints: Getting Started | I'm Stuck Suppose a 27.2 kg child sits 1.82 m to the left of center on the same seesaw. A second child sits at the end on the opposite side, and the system is balanced. (a) Find the mass of the second child. Mchild 2 kg (b) Find the normal force acting at the pivot point. N
Exercise 8.3 Hints: Getting Started | I'm Stuck Suppose a 27.2 kg child sits 1.82 m to the left of center on the same seesaw. A second child sits at the end on the opposite side, and the system is balanced. (a) Find the mass of the second child. Mchild 2 kg (b) Find the normal force acting at the pivot point. N
Principles of Physics: A Calculus-Based Text
5th Edition
ISBN:9781133104261
Author:Raymond A. Serway, John W. Jewett
Publisher:Raymond A. Serway, John W. Jewett
Chapter10: Rotational Motion
Section: Chapter Questions
Problem 73P: A stepladder of negligible weight is constructed as shown in Figure P10.73, with AC = BC = = 4.00...
Related questions
Concept explainers
Angular speed, acceleration and displacement
Angular acceleration is defined as the rate of change in angular velocity with respect to time. It has both magnitude and direction. So, it is a vector quantity.
Angular Position
Before diving into angular position, one should understand the basics of position and its importance along with usage in day-to-day life. When one talks of position, it’s always relative with respect to some other object. For example, position of earth with respect to sun, position of school with respect to house, etc. Angular position is the rotational analogue of linear position.
Question
![55 PM Sun Dec 18
Substitute all known quantities.
Solve for x substituting the normal force found in
part (b).
webassign.net à
-(75.7 kg)(9.80 m/s2)(2.46 m + x) + (57.8 kg) (9.80
m/s²)(0) - (12.0 kg) (9.80 m/s2)(2.46 m) + n(2.46
m) = 0
-(1.82 x 10³ N-m) - (741.86)x - (289.296 N-m) +
(2.46 m)n=0
Exercise 8.3
X
Remarks The answers for x in parts (a) and (c) agree except for a small round-off discrepancy. This illustrates
how choosing a different axis leads to the same solution.
m
Hints: Getting Started | I'm Stuck
Suppose a 27.2 kg child sits 1.82 m to the left of center on the same seesaw. A
second child sits at the end on the opposite side, and the system is balanced.
(a) Find the mass of the second child.
mchild 2
kg
(b) Find the normal force acting at the pivot point.
N](/v2/_next/image?url=https%3A%2F%2Fcontent.bartleby.com%2Fqna-images%2Fquestion%2Fd34f71a4-c848-420f-866d-4e9ee3fcb925%2F5dc0239d-bf6a-45d3-a110-1bc3a97ee533%2Fk7l0k4_processed.jpeg&w=3840&q=75)
Transcribed Image Text:55 PM Sun Dec 18
Substitute all known quantities.
Solve for x substituting the normal force found in
part (b).
webassign.net à
-(75.7 kg)(9.80 m/s2)(2.46 m + x) + (57.8 kg) (9.80
m/s²)(0) - (12.0 kg) (9.80 m/s2)(2.46 m) + n(2.46
m) = 0
-(1.82 x 10³ N-m) - (741.86)x - (289.296 N-m) +
(2.46 m)n=0
Exercise 8.3
X
Remarks The answers for x in parts (a) and (c) agree except for a small round-off discrepancy. This illustrates
how choosing a different axis leads to the same solution.
m
Hints: Getting Started | I'm Stuck
Suppose a 27.2 kg child sits 1.82 m to the left of center on the same seesaw. A
second child sits at the end on the opposite side, and the system is balanced.
(a) Find the mass of the second child.
mchild 2
kg
(b) Find the normal force acting at the pivot point.
N
![(a) Where should the man sit to balance the
seesaw?
Apply the second condition of equilibrium to the
plank by setting the sum of the torques equal to
zero.
The first two torques are zero. Let x represent the
man's distance from the pivot. The woman is at a
distance L/2 from the pivot.
Solve this equation for x and evaluate it.
(b) Find the normal force n exerted by the pivot on
the seesaw.
Apply the first condition of equilibrium to the plank,
solving the resulting equation for the unknown
normal force, n.
(c) Repeat part (a), choosing a new axis through the
left end of the plank.
Compute the torques using this axis, and set their
sum equal to zero. Now the pivot and gravity forces
on the plank result in nonzero torques.
Substitute all known quantities.
Solve for x substituting the normal force found in
part (b)..
pivot + gravity+man+woman-0
0+ 0 Mgx + mg(L/2) - 0
m (L/2)
M
x 1.878
=
(57.8 kg) (2.46 m)
75.7 kg
m
-Mg-mg - mp9 + n = 0
n = (M + m + mpig
= (75.7 kg + 57.8 kg + 12.0 kg) (9.80 m/s²)
n= 1425.9
N
+
pivot gravity + man + woman = 0
-Mg(L/2 + x) + mg(0) - mp19(L/2) + n(L/2) = 0
-(75.7 kg) (9.80 m/s2) (2.46 m + x) + (57.8 kg) (9.80
m/s²) (0) (12.0 kg) (9.80 m/s2) (2.46 m) + n(2.46
m) = 0
-(1.82 x 10³ N-m) - (741.86)x (289.296 N-m) +
(2.46 m)n = 0
-](/v2/_next/image?url=https%3A%2F%2Fcontent.bartleby.com%2Fqna-images%2Fquestion%2Fd34f71a4-c848-420f-866d-4e9ee3fcb925%2F5dc0239d-bf6a-45d3-a110-1bc3a97ee533%2Fhv5mzwq_processed.jpeg&w=3840&q=75)
Transcribed Image Text:(a) Where should the man sit to balance the
seesaw?
Apply the second condition of equilibrium to the
plank by setting the sum of the torques equal to
zero.
The first two torques are zero. Let x represent the
man's distance from the pivot. The woman is at a
distance L/2 from the pivot.
Solve this equation for x and evaluate it.
(b) Find the normal force n exerted by the pivot on
the seesaw.
Apply the first condition of equilibrium to the plank,
solving the resulting equation for the unknown
normal force, n.
(c) Repeat part (a), choosing a new axis through the
left end of the plank.
Compute the torques using this axis, and set their
sum equal to zero. Now the pivot and gravity forces
on the plank result in nonzero torques.
Substitute all known quantities.
Solve for x substituting the normal force found in
part (b)..
pivot + gravity+man+woman-0
0+ 0 Mgx + mg(L/2) - 0
m (L/2)
M
x 1.878
=
(57.8 kg) (2.46 m)
75.7 kg
m
-Mg-mg - mp9 + n = 0
n = (M + m + mpig
= (75.7 kg + 57.8 kg + 12.0 kg) (9.80 m/s²)
n= 1425.9
N
+
pivot gravity + man + woman = 0
-Mg(L/2 + x) + mg(0) - mp19(L/2) + n(L/2) = 0
-(75.7 kg) (9.80 m/s2) (2.46 m + x) + (57.8 kg) (9.80
m/s²) (0) (12.0 kg) (9.80 m/s2) (2.46 m) + n(2.46
m) = 0
-(1.82 x 10³ N-m) - (741.86)x (289.296 N-m) +
(2.46 m)n = 0
-
Expert Solution
![](/static/compass_v2/shared-icons/check-mark.png)
This question has been solved!
Explore an expertly crafted, step-by-step solution for a thorough understanding of key concepts.
This is a popular solution!
Trending now
This is a popular solution!
Step by step
Solved in 2 steps
![Blurred answer](/static/compass_v2/solution-images/blurred-answer.jpg)
Knowledge Booster
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, physics and related others by exploring similar questions and additional content below.Recommended textbooks for you
![Principles of Physics: A Calculus-Based Text](https://www.bartleby.com/isbn_cover_images/9781133104261/9781133104261_smallCoverImage.gif)
Principles of Physics: A Calculus-Based Text
Physics
ISBN:
9781133104261
Author:
Raymond A. Serway, John W. Jewett
Publisher:
Cengage Learning
![Physics for Scientists and Engineers, Technology …](https://www.bartleby.com/isbn_cover_images/9781305116399/9781305116399_smallCoverImage.gif)
Physics for Scientists and Engineers, Technology …
Physics
ISBN:
9781305116399
Author:
Raymond A. Serway, John W. Jewett
Publisher:
Cengage Learning
![Glencoe Physics: Principles and Problems, Student…](https://www.bartleby.com/isbn_cover_images/9780078807213/9780078807213_smallCoverImage.gif)
Glencoe Physics: Principles and Problems, Student…
Physics
ISBN:
9780078807213
Author:
Paul W. Zitzewitz
Publisher:
Glencoe/McGraw-Hill
![Principles of Physics: A Calculus-Based Text](https://www.bartleby.com/isbn_cover_images/9781133104261/9781133104261_smallCoverImage.gif)
Principles of Physics: A Calculus-Based Text
Physics
ISBN:
9781133104261
Author:
Raymond A. Serway, John W. Jewett
Publisher:
Cengage Learning
![Physics for Scientists and Engineers, Technology …](https://www.bartleby.com/isbn_cover_images/9781305116399/9781305116399_smallCoverImage.gif)
Physics for Scientists and Engineers, Technology …
Physics
ISBN:
9781305116399
Author:
Raymond A. Serway, John W. Jewett
Publisher:
Cengage Learning
![Glencoe Physics: Principles and Problems, Student…](https://www.bartleby.com/isbn_cover_images/9780078807213/9780078807213_smallCoverImage.gif)
Glencoe Physics: Principles and Problems, Student…
Physics
ISBN:
9780078807213
Author:
Paul W. Zitzewitz
Publisher:
Glencoe/McGraw-Hill
![University Physics Volume 1](https://www.bartleby.com/isbn_cover_images/9781938168277/9781938168277_smallCoverImage.gif)
University Physics Volume 1
Physics
ISBN:
9781938168277
Author:
William Moebs, Samuel J. Ling, Jeff Sanny
Publisher:
OpenStax - Rice University
![Physics for Scientists and Engineers: Foundations…](https://www.bartleby.com/isbn_cover_images/9781133939146/9781133939146_smallCoverImage.gif)
Physics for Scientists and Engineers: Foundations…
Physics
ISBN:
9781133939146
Author:
Katz, Debora M.
Publisher:
Cengage Learning