/*! 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 32 In a system of particles \(8 \ma... [FREE SOLUTION] | 91Ó°ÊÓ

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In a system of particles \(8 \mathrm{~kg}\) mass is subjected to a force of \(16 \mathrm{~N}\) along \(+\) ve \(x\)-axis and another \(8 \mathrm{~kg}\) mass is subjected to a force of \(8 \mathrm{~N}\) along \(+\) ve \(y\)-axis. The magnitude of acceleration of centre of mass and the angle made by it with \(x\)-axis are given, respectively, by (1) \(\frac{\sqrt{5}}{2} \mathrm{~ms}^{-2}, \theta=45^{\circ}\) (2) \(3 \sqrt{5} \mathrm{~ms}^{-2}, \theta=\tan ^{-2}\left(\frac{2}{3}\right)\) (3) \(\frac{\sqrt{5}}{2} \mathrm{~ms}^{-2}, \theta=\tan ^{-1}\left(\frac{1}{2}\right)\) (4) \(1 \mathrm{~ms}^{-2}, \theta=\tan ^{-2} \sqrt{3}\)

Short Answer

Expert verified
(3) \(\frac{\sqrt{5}}{2} \text{ ms}^{-2}, \theta=\tan^{-1}\left(\frac{1}{2}\right)\)

Step by step solution

01

Calculate Total Force on System

The first mass has a force of \(16 \text{ N}\) in the \(+x\)-direction, and the second mass has a force of \(8 \text{ N}\) in the \(+y\)-direction. To find the total force on the system, combine these vectorially: \(\mathbf{F} = (16 \text{ N}, 0 \text{ N}) + (0 \text{ N}, 8 \text{ N}) = (16 \text{ N}, 8 \text{ N})\).
02

Calculate Total Mass of System

The total mass of the system is simply the sum of the masses: \(8 \text{ kg} + 8 \text{ kg} = 16 \text{ kg}\).
03

Calculate the Acceleration of Centre of Mass

Using Newton’s second law, the acceleration of the center of mass \(\mathbf{a_{cm}}\) can be calculated as \(\mathbf{a_{cm}} = \frac{\sum \mathbf{F}}{\sum m}\). Substituting the values gives: \(\mathbf{a_{cm}} = \frac{(16 \text{ N}, 8 \text{ N})}{16 \text{ kg}} = (1 \text{ m/s}^2, 0.5 \text{ m/s}^2)\).
04

Calculate Magnitude of Acceleration of Centre of Mass

The magnitude of \(\mathbf{a_{cm}}\) is calculated using the Pythagorean theorem: \(|\mathbf{a_{cm}}| = \sqrt{(1)^2 + (0.5)^2} = \sqrt{1.25} = \frac{\sqrt{5}}{2} \text{ m/s}^2\).
05

Determine the Angle with x-Axis

The angle \(\theta\) that the acceleration vector makes with the \(x\)-axis is calculated using the tangent function: \(\tan(\theta) = \frac{0.5}{1} = 0.5\). Therefore, \(\theta = \tan^{-1}(0.5)\).
06

Compare Results with Options

The calculated magnitude is \(\frac{\sqrt{5}}{2} \text{ m/s}^2\) and the angle is \(\tan^{-1}\left(\frac{1}{2}\right)\). These match option (3), \(\frac{\sqrt{5}}{2} \text{ m/s}^2, \theta = \tan^{-1}\left(\frac{1}{2}\right)\).

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Key Concepts

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

Newton's Second Law
Newton's Second Law is a fundamental principle in physics that states the relationship between force, mass, and acceleration. It is often expressed by the equation \( F = ma \), where \( F \) represents the net force acting on an object, \( m \) is the mass of the object, and \( a \) is the acceleration. This law implies that the acceleration of an object is directly proportional to the net force acting on it and inversely proportional to its mass.When applied to a system of particles, the acceleration of the center of mass can be determined by dividing the sum of the forces acting on the system by the total mass. This provides insight into how forces collectively influence motion, enabling our understanding of the dynamic behavior of the system as a whole. Newton’s Second Law is essential for solving many problems in mechanics, especially those involving multiple forces acting on different components of a system.
Vector Addition
In physics, vector addition is a method of combining two or more vectors to determine their cumulative effect. Vectors are quantities that have both magnitude and direction, such as force or velocity. In order to perform vector addition, one must consider both the magnitude and direction of each vector.When dealing with forces, vector addition involves using the component form of vectors, aligning them along coordinate axes such as the \( x \)-axis and \( y \)-axis. For example, a force of \( 16 \text{ N} \) along the \( x \)-axis and another force of \( 8 \text{ N} \) along the \( y \)-axis can be combined to form a resultant force vector \( (16 \text{ N}, 8 \text{ N}) \). The process of vector addition is crucial for accurately calculating the net force acting on a system, which in turn affects the acceleration and ultimate motion of the objects involved.
Pythagorean Theorem
The Pythagorean theorem is a mathematical principle that relates the sides of a right triangle. It states that the square of the length of the hypotenuse (the side opposite the right angle) is equal to the sum of the squares of the lengths of the other two sides. In formulaic terms, \( a^2 + b^2 = c^2 \), where \( c \) is the hypotenuse.In physics, the Pythagorean theorem is frequently used to determine the magnitude of a resultant vector, especially when resolving forces or accelerations into their components. For example, if a system has accelerations of \( 1 \text{ m/s}^2 \) in the \( x \)-direction and \( 0.5 \text{ m/s}^2 \) in the \( y \)-direction, the Pythagorean theorem helps us calculate the overall magnitude of the acceleration vector as \( \sqrt{1^2 + 0.5^2} = \frac{\sqrt{5}}{2} \text{ m/s}^2 \). This geometric approach simplifies the calculation of combined vector magnitudes in various contexts.
Trigonometry in Physics
Trigonometry plays a pivotal role in physics, especially when dealing with angles and vector components. It helps relate the sides of a right triangle to its angles, using functions such as sine, cosine, and tangent. These functions allow us to break down vectors into their horizontal and vertical components or calculate angles based on given side lengths.In the context of calculating the acceleration of the center of mass, trigonometric functions are used to determine the angle that the resultant vector makes with a given axis. By using the tangent function, which is defined as the ratio of the opposite side to the adjacent side in a right triangle, we can find the angle \( \theta \) such that \( \tan(\theta) = \frac{{\text{opposite}}}{{\text{adjacent}}} \). For our example, this translates to \( \tan(\theta) = \frac{0.5}{1} \), resulting in \( \theta = \tan^{-1}(0.5) \).Understanding how to apply trigonometry in physics is essential for solving problems involving directions and angles, as it provides the tools needed to accurately analyze and represent vector quantities.

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Most popular questions from this chapter

Block \(A\) of mass \(M=2 \mathrm{~kg}\) is connected to another block \(B\) of mass \(m=1 \mathrm{~kg}\) with a string and a spring of force constant \(k=600 \mathrm{~N} / \mathrm{m}\) as shown in figure. Initially, spring is compressed to \(10 \mathrm{~cm}\) and whole system is moving on a smooth surface with a velocity \(v=1 \mathrm{~m} / \mathrm{s}\). At any time, thread is burnt, the velocity of block \(A\), when \(B\) is having maximum velocity w.r.t. ground, is (1) zero (2) \(1 \mathrm{~m} / \mathrm{s}\) (3) \(3 \mathrm{~m} / \mathrm{s}\) (4) none of these

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