Question

A body of mass m is dropped from a height h equal to the radius of the earth (R) above the tunnel dug through the earth as shown in the figure. Ignore the effect of earths rotation and air resistance, M is mass of earth. Choose the correct alternative(s):

• A. body will oscillate through the earth to a height h on both sides
• B. body will execute simple harmonic motion.
• C. Motion of the body is periodic.
• D. body passes the center of earth with a speed $\sqrt{\frac{2GM}{R}}$

Answer 1

The correct option is C Motion of the body is periodic.

The motion of the body will be to and from the motion of the body will get down at last end by gravity will attract it and it will come back to maximum height and the again gravitational attraction will be more and it will once again go down and this will continuously happen and the body will remain in motion in tunnel and so we can say motion of the body is periodic.