Home » 2011 » June » 06

# Daily Archives: June 6, 2011

## Online Counselling for Admission to Engineering Colleges start on 11 June 2011

Candidates with valid AIEEE scores can start online registration at Central Counselling Board (CRB) from 11 June 2011.

The candidates can register, fill choices, see indicative seat allotment and lock choices till 23 June 2011.

The first round of allotment starts on 25 June 2011

If seat allotted in first round, the candidates can report to the reporting centre and give options from June 26 to July 2

Get more details here

You can find the opening and closing ranks for NITs 2010  here

Get the Tentative Admission Schedule HERE

If seat not allotted, the candidates can watch the CCB website (http://ccb.nic.in/) fro round 2 of allotment on 5 July 2011.

The third round of allotment will be on 13 July and classes will start from 21 July 2011.

## Ball falls to earth, and earth moves to ball?!!

Sandeepan Dhar Choudhary asked:

“When the ball falls on the earth, the earth also moves up to meet it. But the motion of the earth is not noticeable. Explain why?”

The force exerted by the ball on earth is same as the force exerted by the earth on the ball. The acceleration of the ball towards earth is approximately 10 m/s2.

The acceleration of earth towards the ball = force/mass of earth ≈ 10-23 m/s2

When the earth moves towards the ball with this acceleration, the time required to travel the distance will be very large. If we assume a distance of 1m, and from the equation

$S=ut+\frac{1}{2}at^{2}$

we get t ≈ 1012 seconds whereas the ball reaches the earth in 0.4 seconds

[warning]In a nut shell, we can say that we cannot notice the motion of earth towards the ball due to the extremely low value of acceleration of earth towards the ball.[/warning]

What is torsion?