Two small and heavy sphere, each of mass \(\mathrm{M}\), are placed distance r apart on a horizontal surface the gravitational potential at a mid point on the line joining the center of spheres is (A) zero (B) \(-(\mathrm{GM} / \mathrm{r})\) (C) \(-[(2 \mathrm{GM}) / \mathrm{r}]\) (D) \(-[(4 \mathrm{GM}) / \mathrm{r}]\)

Short Answer

Expert verified
The short version of the answer is: The gravitational potential at the midpoint on the line joining the centers of the two spheres is given by the sum of the gravitational potentials due to each sphere at that point. Since the midpoint is equidistant from both spheres, we find the potential due to each sphere and add them: \(V = V_{1} + V_{2} = (-\frac{2GM}{r}) + (-\frac{2GM}{r}) = -(\frac{4GM}{r})\) Hence, the correct answer is (D) \(-\frac{4GM}{r}\).

Step by step solution

01

Identify Variables

Identify the important variables in the problem: mass of both spheres (M), distance between the centers of spheres (r), and the gravitational potential at the midpoint (V).
02

Understand Gravitational Potential Formula

Gravitational potential V at a given point due to a mass M is given by the formula: \(V = -\frac{GM}{r}\) where G is the gravitational constant, r is the distance from the point to the mass, and M is the mass.
03

Determine the Distance from each Sphere to the Midpoint

As we need the gravitational potential at the midpoint of the line connecting the centers of the spheres, we need to determine the distance from each sphere center to the midpoint. Since it's the midpoint, both distances will be the same: \(r_{1} = r_{2} = \frac{r}{2}\)
04

Compute Gravitational Potential due to each Sphere at the Midpoint

Using the gravitational potential formula \(V = -\frac{GM}{r}\), we'll need to find the gravitational potential at the midpoint caused by both spheres. We'll call these potentials V1 and V2. For Sphere 1: \(V_{1} = -\frac{GM}{r_{1}} = -\frac{GM}{\frac{r}{2}} = -\frac{2GM}{r}\) For Sphere 2: \(V_{2} = -\frac{GM}{r_{2}} = -\frac{GM}{\frac{r}{2}} = -\frac{2GM}{r}\)
05

Add Gravitational Potentials at the Midpoint

Now, we need to add the gravitational potentials (V1 and V2) at the midpoint caused by both spheres: Total Gravitational Potential (V) at Midpoint: \(V = V_{1} + V_{2} = (-\frac{2GM}{r}) + (-\frac{2GM}{r}) = -(\frac{4GM}{r})\)
06

Compare the Result to the Given Options

Comparing the calculated gravitational potential \( -\frac{4GM}{r} \) to the given options in the exercise, we see that it matches option (D). Therefore, the correct answer is (D) \(-\frac{4GM}{r}\).

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

Which one of following statements regarding artificial satellite of earth is incorrect (A) The orbital velocity depends on the mass of the satellite (B) A minimum velocity of \(8 \mathrm{kms}^{-1}\) is required by a satellite to orbit quite close to the earth. (C) The period of revolution is large if the radius of its orbit is large (D) The height of geostationary satellite is about \(36000 \mathrm{~km}\) from earth

The Gravitational P.E. of a body of mass \(\mathrm{m}\) at the earth's surface is \(-\mathrm{mgRe}\). Its gravitational potential energy at a height \(\operatorname{Re}\) from the earth's surface will be \(=\ldots \ldots \ldots\) here (Re is the radius of the earth) (A) \(-2 \mathrm{mgRe}\) (B) \(2 \mathrm{mgRe}\) (C) \((1 / 2) \mathrm{mg} \mathrm{Re}\) (D) \(-(1 / 2) \mathrm{mg} \operatorname{Re}\)

A body weights \(700 \mathrm{~g} \mathrm{wt}\) on the surface of earth. How much it weight on the surface of planet whose mass is \(1 / 7\) and radius is half that of the earth (A) \(200 \mathrm{~g} \mathrm{wt}\) (B) \(400 \mathrm{~g} \mathrm{wt}\) (C) \(50 \mathrm{~g} \mathrm{wt}\) (D) \(300 \mathrm{~g}\) wt.

The mass of a space ship is \(1000 \mathrm{~kg} .\) It is to be launched from earth's surface out into free space the value of \(\mathrm{g}\) and \(\mathrm{R}\) (radius of earth) are \(10 \mathrm{~ms}^{-2}\) and \(6400 \mathrm{~km}\) respectively the required energy for this work will be $=\ldots \ldots \ldots .$ J (A) \(6.4 \times 10^{11}\) (B) \(6.4 \times 10^{8}\) (C) \(6.4 \times 10^{9}\) (D) \(6.4 \times 10^{10}\)

The maximum and minimum distance of a comet from the sun are $8 \times 10^{12} \mathrm{~m}\( and \)1.6 \times 10^{12} \mathrm{~m} .$ If its velocity when nearest to the sun is \(60 \mathrm{~ms}^{-1}\), What will be its velocity in \(\mathrm{ms}^{-1}\) when it is farthest? (A) 6 (B) 12 (C) 60 (D) 112

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