Chapter 18: Problem 4
Calculate the position of the centre of mass of \(2 \mathrm{~kg}\) placed at \(x=1,3 \mathrm{~kg}\) placed at \(x=4,1 \mathrm{~kg}\) placed at \(x=6\) and \(6 \mathrm{~kg}\) placed at \(x=-5\).
Short Answer
Expert verified
The center of mass is at \(-\frac{5}{6}\).
Step by step solution
01
Understand the Centre of Mass Formula
The center of mass (COM) for a system of particles can be found using the formula: \( x_{\text{COM}} = \frac{m_1x_1 + m_2x_2 + m_3x_3 + \cdots}{m_1 + m_2 + m_3 + \cdots} \). Here, \( m_i \) are the masses and \( x_i \) are their positions on a one-dimensional line.
02
Assign Given Values
List the masses and their corresponding positions: \( m_1 = 2 \) kg at \( x_1 = 1 \), \( m_2 = 3 \) kg at \( x_2 = 4 \), \( m_3 = 1 \) kg at \( x_3 = 6 \), \( m_4 = 6 \) kg at \( x_4 = -5 \).
03
Calculate the Numerator
Using the formula, calculate the sum of the products of masses and positions: \( m_1x_1 + m_2x_2 + m_3x_3 + m_4x_4 = (2 \times 1) + (3 \times 4) + (1 \times 6) + (6 \times -5) \).
04
Compute the Numerator
Calculate the above expression: \( 2 + 12 + 6 - 30 = -10 \).
05
Calculate the Denominator
Find the total mass: \( m_1 + m_2 + m_3 + m_4 = 2 + 3 + 1 + 6 \).
06
Compute the Denominator
Calculate the total mass: \( 2 + 3 + 1 + 6 = 12 \).
07
Calculate Centre of Mass
Use the values obtained to find the center of mass: \( x_{\text{COM}} = \frac{-10}{12} \).
08
Simplify the Result
Simplify the fraction: \( x_{\text{COM}} = -\frac{10}{12} = -\frac{5}{6} \).
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 91Ó°ÊÓ!
Key Concepts
These are the key concepts you need to understand to accurately answer the question.
Understanding the Centre of Mass Formula
The centre of mass formula is a fundamental tool in physics and mathematics. It helps us find the point where the mass of a system is concentrated. This point is known as the centre of mass (COM). The formula used to calculate the centre of mass for a system of particles is:
- \[ x_{\text{COM}} = \frac{m_1x_1 + m_2x_2 + m_3x_3 + \cdots}{m_1 + m_2 + m_3 + \cdots} \]
- \(m_i\) represents the mass of each particle in the system.
- \(x_i\) represents the position of each mass on the line.
Exploring the System of Particles
A system of particles refers to multiple masses that interact or are related to each other in some context. In the given problem, we have a system consisting of four particles with different masses and positions on a one-dimensional line:
- 2 kg at position 1.
- 3 kg at position 4.
- 1 kg at position 6.
- 6 kg at position -5.
Navigating the One-Dimensional Line
When calculating the centre of mass, we often consider a one-dimensional line, making it simpler to map positions. A one-dimensional line is like a straight number line where each point is defined by a single coordinate or position value. In our problem:
- The particles are positioned at defined points: 1, 4, 6, and -5.
- These positions help us determine where each mass is located relative to the others.
Engaging in Mathematics Problem Solving
Mathematics problem solving is both an art and science that requires a clear understanding of concepts and a methodical approach. Solving for the centre of mass involves several crucial steps:
- Listing all given data such as masses and positions.
- Applying the centre of mass formula to compute the sum of mass-position products and total mass.
- Solving for \( x_{\text{COM}} \) from these values.
- Simplifying the results to find the precise location of the centre of mass.