/*! 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} Problem 1 Three particles of mass \(1.0 \m... [FREE SOLUTION] | 91Ó°ÊÓ

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Three particles of mass \(1.0 \mathrm{~kg}, 2.0 \mathrm{~kg}\), and \(3.0 \mathrm{~kg}\) are placed at the vertices \(A, B\), and \(C\), respectively, of an equilateral triangle \(A B C\) of edge \(1.0 \mathrm{~m}\) (Fig 9-23). Find the distance of their center of mass from \(A\).

Short Answer

Expert verified
The distance from point A to the center of mass is approximately 0.726 meters.

Step by step solution

01

Understand the Problem

We need to find the center of mass of three particles placed at the vertices of an equilateral triangle and determine the distance of this center from one of the vertices, labeled as point A.
02

Identify the Coordinates

Assign coordinates to the vertices of the equilateral triangle where point A is placed at the origin (0,0), point B is at (1,0), and point C, based on equilateral triangle properties, is at (0.5, \(\sqrt{3}/2\)).
03

Calculate the Center of Mass

The formula for the center of mass (COM) for multiple particles is: \( \text{COM}_x = \frac{m_1x_1 + m_2x_2 + m_3x_3}{m_1+m_2+m_3} \) and \( \text{COM}_y = \frac{m_1y_1 + m_2y_2 + m_3y_3}{m_1+m_2+m_3} \).Plug in the values: - \( m_1 = 1 \), \( x_1 = 0 \), \( y_1 = 0 \)- \( m_2 = 2 \), \( x_2 = 1 \), \( y_2 = 0 \)- \( m_3 = 3 \), \( x_3 = 0.5 \), \( y_3 = \sqrt{3}/2 \)Calculate \( \text{COM}_x = \frac{1(0) + 2(1) + 3(0.5)}{6} = \frac{3.5}{6} \approx 0.583 \).Calculate \( \text{COM}_y = \frac{1(0) + 2(0) + 3(\sqrt{3}/2)}{6} = \frac{3(\sqrt{3}/2)}{6} = \frac{\sqrt{3}}{4} \approx 0.433 \).
04

Find the Distance from Point A

Use the distance formula \( d = \sqrt{(\text{COM}_x - 0)^2 + (\text{COM}_y - 0)^2} \) to find the distance from point A to the center of mass.Calculate \( d = \sqrt{0.583^2 + 0.433^2} \).\( d \approx \sqrt{0.34 + 0.187} = \sqrt{0.527} \approx 0.726 \text{ m} \).

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Key Concepts

These are the key concepts you need to understand to accurately answer the question.

Equilateral Triangle
An equilateral triangle is a fascinating geometric shape where all sides are of the same length. For our exercise, this is noted where the particles are placed at the vertices of such a triangle, each side being 1 meter long. A few things to remember about equilateral triangles are:
  • All three sides are equal.
  • All three internal angles are 60 degrees.
  • The center of the triangle (centroid) divides the median in a 2:1 ratio.
If you visualize the triangle, start by setting one of its vertices (point A) at the origin of a coordinate plane. Its coordinates are then (0,0). The second vertex (point B) is straightforwardly placed at (1,0), because the distance between A and B is 1 meter. For the third vertex (point C), it sits directly at (0.5, \(\sqrt{3}/2\)). This position stems from how equilateral triangles position themselves symmetrically about the coordinate axes. Understanding these properties is essential because it helps us place particles at precise points and further analyze the system by calculating relationships, such as the center of mass.
Mass Distribution
In this exercise, mass distribution involves the placement of different masses at different vertices of the triangle. Let's explore how this works:
  • The three masses in our example are 1 kg at point A, 2 kg at point B, and 3 kg at point C.
  • Each mass has its own positional influence on where the combined center of mass lies.
The center of mass is similar to finding an average location for all the masses, weighted according to their respective magnitudes. Because the masses have different values, the larger mass (3 kg) at point C has more 'say' in where the center of mass will be located compared to the smaller mass at point A. By calculating averaged positions, including the different weights of each particle's mass, we uncover a central point of equilibrium. This point is where the mass distribution is perfectly balanced, enabling further calculations, like determining distances or forces.
Distance Formula
The distance formula is a mathematical tool that helps find the distance between two points in a coordinate plane. This is particularly useful for determining how far the center of mass is from the origin point A. Here's a refresher on how it works:
  • The distance formula is \( d = \sqrt{(x_2 - x_1)^2 + (y_2 - y_1)^2} \).
  • In our exercise, as point A is at the origin (0,0), the formula simplifies to \( d = \sqrt{(\text{COM}_x)^2 + (\text{COM}_y)^2} \).
Using this adjusted version, we plug in the previously determined coordinates for the center of mass (COM), \( x \approx 0.583 \) and \( y \approx 0.433 \).
Calculating further gives us the distance \( d \approx 0.726 \) meters. This distance represents the direct line across space from point A to the calculated center of mass, encapsulating both horizontal and vertical position changes. Understanding and using the distance formula is key to quantifying spatial relationships within the triangle.

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Most popular questions from this chapter

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