Log out Go to App
Go to App

Learning Materials

Features

Discover

Chapter 4: Q58P (page 781)

(a) Calculate the potential energy of a system of two small spheres, one carrying a charge of 2.00C and the other a charge of -3.50μC, with their centers separated by a distance of 0.180 m. Assume that U = 0 when the charges are infinitely separated. (b) Suppose that one sphere is held in place; the other sphere, with a mass of 1.50 g, is shot away from it. What minimum initial speed would the moving sphere need to escape completely from the attraction of the fixed sphere? (To escape, the moving sphere would have to reach a velocity of zero when it is infinitely far from the fixed sphere.)

Short Answer

Expert verified

a) The potential energy is U=-0.252]

b) Initial speed is Va=18.3m/s

Step by step solution

01

Step-by-Step Solution

Given data:

Q1=-3.50cQ2=2.0μCd=0.25mm=1.5g

02

Step 2:

So, the potential between two-point charges is

U=kQ1Qd=9×109×2.0×10-6×-3.5×10-60.25=-0.252J

Hence, the potential energy is.

Using conservation law:

Ka+Ua=Kb+UbKa=-Ua=0.252J

Here Kbis zero and (v) is also zero because the potential is inversely proportional to (r) therefore Kbis

Ka=12mv2=0.252

So,

va=2×0.251.5×10-3=18.3mls

Therefore, the initial speed is18.3mls.

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.

Start your free trial

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

Light Bulbs in Series and in Parallel. Two light bulbs have constant resistances of 400Ωand 800Ω. If the two light bulbs are connected in series across a 120Vline, find (a) the current through each bulb; (b) the power dissipated in each bulb; (c) the total power dissipated in both bulbs. The two light bulbs are now connected in parallel across the120Vline. Find (d) the current through each bulb; (e) the power dissipated in each bulb; (f) the total power dissipated in both bulbs. (g) In each situation, which of the two bulbs glows the brightest? (h) In which situation is there a greater total light output from both bulbs combined?

A heart defibrillator is used to enable the heart to start beating if it has stopped. This is done by passing a large current of12Athrough the body at25Vfor a very short time, usually3.0msabout . (a) What power does the defibrillator deliver to the body, and (b) how much energy is transferred ?

A particle of mass 0.195 g carries a charge of-2.50×10-8C. The particle is given an initial horizontal velocity that is due north and has magnitude4.00×104m/s. What are the magnitude and direction of the minimum magnetic field that will keepthe particle moving in the earth’s gravitational field in the samehorizontal, northward direction?

A typical small flashlight contains two batteries, each having an emf of1.5V, connected in series with a bulb having resistance17Ω. (a) If the internal resistance of the batteries is negligible, what power is delivered to the bulb? (b) If the batteries last for1.5hwhat is the total energy delivered to the bulb? (c) The resistance of real batteries increases as they run down. If the initial internal resistance is negligible, what is the combined internal resistance of both batteries when the power to the bulb has decreased to half its initial value? (Assume that the resistance of the bulb is constant. Actually, it will change somewhat when the current through the filament changes, because this changes the temperature of the filament and hence the resistivity of the filament wire.)

The magnetic force on a moving charged particle is always perpendicular to the magnetic fieldB→. Is the trajectory of a moving charged particle always perpendicular to the magnetic field lines? Explain your reasoning.
See all solutions

Recommended explanations on Physics Textbooks

Measurements

Read Explanation

Fields in Physics

Read Explanation

Oscillations

Read Explanation

Wave Optics

Read Explanation

Electricity and Magnetism

Read Explanation

Space Physics

Read Explanation
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