The escape velocity of a body on the surface of the earth is $11.2 \mathrm{~km} / \mathrm{sec}$. If the mass of the earth is increases to twice its present value and the radius of the earth becomes half, the escape velocity becomes \(=\ldots \ldots \ldots \ldots \mathrm{kms}^{-1}\) \((\Delta) 56\)

Short Answer

Expert verified
The new escape velocity when the Earth's mass is doubled and the radius becomes half is \(44.8 \mathrm{~km/sec}\).

Step by step solution

01

Find the initial escape velocity

We are given that the escape velocity on the surface of the Earth is currently 11.2 km/sec. Convert this to meters per second for calculations: \[v_e = 11.2 \times 1000 \mathrm{~m/sec}\]
02

Calculate the gravitational constant times the Earth's mass

Using the escape velocity formula and the given Earth's radius \(R\) as 6400km or 6400,000m, we can solve for the product of the mass and the gravitational constant as follows: \[\frac{GM}{R} = \frac{v_e^2}{2\RE\] \[GM = (v_e^2)(\frac{R}{2})\]
03

Write the equation for the new escape velocity

Let's denote the new mass as \(M'\), which is twice the current mass, and the new radius as \(R'\), which is half the current radius. Then, the escape velocity formula can be written as: \[v'_e = \sqrt{\frac{2 GM'}{R'}}\]
04

Solve for the new escape velocity

Substituting the values of \(M'\) and \(R'\) into the new escape velocity formula, we get: \[v'_e = \sqrt{\frac{2 G(2M)}{\frac{R}{2}}}\] \[v'_e = \sqrt{\frac{4 GM}{\frac{R}{2}}}\] \[v'_e = \sqrt{\frac{4 (v_e^2)(\frac{R}{2})}{\frac{R}{2}}}\] As we plug in the initial escape velocity value from Step 1, and cancel terms as needed: \[v'_e = \sqrt{\frac{4 (11.2 \times 1000)^2}{1}}\] \[v'_e = 4 \times 11.2 \times 1000 \mathrm{~m/sec}\] \[v'_e = 44.8 \times 1000 \mathrm{~m/sec}\]
05

Convert the new escape velocity to km/sec

Finally, convert the new escape velocity back to km/sec: \[v'_e = 44.8 \mathrm{~km/sec}\] The new escape velocity is 44.8 km/sec.

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

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