Consider a two-particle system with the particles having masses \(\mathrm{M}_{1}\), and \(\mathrm{M}_{2}\). If the first particle is pushed towards the centre of mass through a distance \(d\), by what distance should the second particle be moved so as to keep the centre of mass at the same position? $\\{\mathrm{A}\\}\left[\left(\mathrm{M}_{1} \mathrm{~d}\right) /\left(\mathrm{M}_{1}+\mathrm{M}_{2}\right)\right]$ $\\{\mathrm{B}\\}\left[\left(\mathrm{M}_{2} \mathrm{~d}\right) /\left(\mathrm{M}_{1}+\mathrm{M}_{2}\right)\right]$ $\\{\mathrm{C}\\}\left[\left(\mathrm{M}_{1} \mathrm{~d}\right) /\left(\mathrm{M}_{2}\right)\right]$ $\\{\mathrm{D}\\}\left[\left(\mathrm{M}_{2} \mathrm{~d}\right) /\left(\mathrm{M}_{1}\right)\right]$

Short Answer

Expert verified
The short answer is: The second particle should be moved by a distance of \(\frac{M_1d}{M_2}\) to keep the center of mass at the same position.

Step by step solution

01

Identify the initial center of mass

We will begin by calculating the initial center of mass for the two-particle system. The center of mass can be calculated using the following formula: \(r_{CM} = \frac{M_1r_1 + M_2r_2}{M_1 + M_2}\) Here, r1 and r2 are the positions of the first and second particles, respectively.
02

Calculate the new position of the first particle

The problem states that the first particle is being pushed towards the center of mass by a distance d. Let's assume that the first particle is initially at the origin, i.e., r1 = 0. The new position of the first particle will now be: \(r_1' = -d\)
03

Find the condition for the center of mass to be constant

The center of mass must remain constant, i.e., the new center of mass rCM' should be equal to rCM. From Step 1, we can write the new center of mass as: \(r_{CM}' = \frac{M_1r_1' + M_2r_2'}{M_1 + M_2}\) As the center of mass remains constant, we can assert: \(r_{CM} = r_{CM}'\) Plugging in the values from Step 1 and Step 2, and replacing r1 with 0, we get: \(\frac{M_1(0) + M_2r_2}{M_1 + M_2} = \frac{M_1(-d) + M_2r_2'}{M_1 + M_2}\)
04

Solve for the new position of the second particle

Now, we solve the equation obtained in Step 3 for r2': \(M_1(0) + M_2r_2 = M_1(-d) + M_2r_2'\) \(M_2r_2 = -M_1d + M_2r_2'\) \(r_2' = \frac{M_1d}{M_2} + r_2\) Since we want to find the distance the second particle must move and not its new position, we need to calculate the difference between r2' and r2: Distance required = \(r_2' - r_2 = \frac{M_1d}{M_2}\) The correct answer is given by the option (C): \(\frac{M_1d}{M_2}\)

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 Vaia!

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

Three particles of the same mass lie in the \((\mathrm{X}, \mathrm{Y})\) plane, The \((X, Y)\) coordinates of their positions are \((1,1),(2,2)\) and \((3,3)\) respectively. The \((X, Y)\) coordinates of the centre of mass are \(\\{\mathrm{A}\\}(1,2)\) \(\\{\mathrm{B}\\}(2,2)\) \(\\{\mathrm{C}\\}(1.5,2)\) \(\\{\mathrm{D}\\}(2,1.5)\)

An automobile engine develops \(100 \mathrm{kw}\) when rotating at a speed of 1800 r.p.m. what torque does it deliver? \(\\{\mathrm{A}\\} 350 \mathrm{Nm} \quad\\{\mathrm{B}\\} 440 \mathrm{Nm}\) \\{C \(\\} 531 \mathrm{Nm} \quad\\{\mathrm{D}\\} 628 \mathrm{Nm}\)

The moment of inertia of a meter scale of mass \(0.6 \mathrm{~kg}\) about an axis perpendicular to the scale and passing through \(30 \mathrm{~cm}\) position on the scale is given by (Breath of scale is negligible). \(\\{\mathrm{A}\\} 0.104 \mathrm{kgm}^{2}\) \\{B \(\\} 0.208 \mathrm{kgm}^{2}\) \(\\{\mathrm{C}\\} 0.074 \mathrm{kgm}^{2}\) \(\\{\mathrm{D}\\} 0.148 \mathrm{kgm}^{2}\)

A circular disc of radius \(R\) is free to oscillate about an axis passing through a point on its rim and perpendicular to its plane. The disc is turned through an angle of \(60 ?\) and released. Its angular velocity when it reaches the equilibrium position will be \(\\{\mathrm{A}\\} \sqrt{(\mathrm{g} / 3 \mathrm{R})}\) \(\\{\mathrm{B}\\} \sqrt{(2 \mathrm{~g} / 3 \mathrm{R})}\) \(\\{\mathrm{C}\\} \sqrt{(2 \mathrm{~g} / \mathrm{R})}\) \(\\{\mathrm{D}\\} 2 \sqrt{(2 \mathrm{~g} / \mathrm{R})}\)

A uniform disc of mass \(\mathrm{M}\) and radius \(\mathrm{R}\) rolls without slipping down a plane inclined at an angle \(\theta\) with the horizontal. If the disc is replaced by a ring of the same mass \(\mathrm{M}\) and the same radius \(R\), the ratio of the frictional force on the ring to that on the disc will be \(\\{\mathrm{A}\\} 3 / 2\) \(\\{B\\} 2\) \(\\{\mathrm{C}\\} \sqrt{2}\) \(\\{\mathrm{D}\\} 1\)

See all solutions

Recommended explanations on English Textbooks

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.

Sign-up for free