Why would anyone try this experiment?

Classical Mechanics Level 4

Swapnil the physicist wanted to perform an experiment similar to that of Galileo performed on the leaning tower of Pisa. So Swapnil went to Burj Khalifa (the tallest building on earth) to perform the experiment. He took a glass sphere and a metallic sphere of similar mass. He drops them together into a wide vacuum tube attached to the side of the building, and recorded their motion with a sensitive camera which allows him to distinguish the finest of details. Which of the following did he observe?

Assumptions and Details

Neglect air resistance.

The metallic sphere comes down first The glass sphere comes down first He didn't observe anything Both come down at the same time

3 solutions

Aditya Kumar
Dec 4, 2015

The metallic sphere has free electrons in it. Due to the magnetic field of earth, an upward EMF is generated which creates an upward force. Hence, the metallic sphere would take more time than the glass sphere(An Insulator)

If the sphere is made of a ferromagnetic metal, it will become magnetized and attracted to the earth. And probably to the building.

Arjen Vreugdenhil - 5 years, 6 months ago

Nope, it is diamagnetic ( Its mine, I know well :P)

Swapnil Das - 5 years, 6 months ago

How you can say the metallic sphere and the glass sphere have the same $\color{#D61F06}{volume}$ and $\color{#3D99F6}{mass }$ ?

Refaat M. Sayed - 5 years, 6 months ago

I think the direction of EMF is not upward.

Surya Prakash - 5 years, 6 months ago

It doesn't matter what the direction of EMF is. Just think of Lenz's law. I mean the basic statement.

Arkadeb Sengupta - 5 years, 6 months ago

Found this link

Swapnil Das - 5 years, 6 months ago

Thank you. @Swapnil Das

Surya Prakash - 5 years, 6 months ago

@Surya Prakash – Mention not :)

Swapnil Das - 5 years, 6 months ago

This was a previous year cbse problem.

Aditya Kumar - 5 years, 6 months ago

@Aditya Kumar – Really? Cool.

Swapnil Das - 5 years, 6 months ago

Apply lenz law

Jatin Narde - 5 years, 4 months ago

Wtf? Who would have thought of that!??!?

Sidharth Shambu - 3 years, 3 months ago

Eeshan Khan
Dec 5, 2015

Neil's Bohr type solution: Since both have same mass, and metals have more density than glass, the metal one will have smaller volume, therefore, smaller radius. Although the centre of masses of both will reach the ground at same time(neglecting the repulsive emf for now),the lowest point of glass sphere will touch down first !this will be observed by the super bino

G Silb
Apr 26, 2019

A conductor pushed through a magnetic field will generate currents to oppose that magnetic field. This is the principle behind generators (wind turbines, hydroelectric dams, etc.)

Why would anyone try this experiment?

3 solutions

0 pending reports