Q. 113.7( 3 Votes )

A tunnel is dug along a diameter if the earth. Find the force on a particle of mass m placed in the tunnel at a distance x from the center.

Answer :

Let the mass of the earth be . Here, we have to find the gravitational field inside a solid sphere. The particle is placed at a distance x from the center. Now, the part outside the sphere of radius x, will have no influence on it as the electric field inside a spherical shell is zero. Hence, only the mass up to x will contribute to the electric field.

The density is uniform. Therefore, mass of the sphere would then be

Now the gravitational force on the particle at a distance x is

Rate this question :

How useful is this solution?
We strive to provide quality solutions. Please rate us to serve you better.
Related Videos
Getting the basics of Gravitation51 mins
Try our Mini CourseMaster Important Topics in 7 DaysLearn from IITians, NITians, Doctors & Academic Experts
Dedicated counsellor for each student
24X7 Doubt Resolution
Daily Report Card
Detailed Performance Evaluation
view all courses