## Happy New Year

**Ask Physics** wishes all its members a very **Happy New Year**

## TENSILE FAILURE STERSS

john Alexander asks

Is the **energy** required to break a sample of string proportional to the **length** of string or is the **energy** requirednto break the sting constant?

**Ans**

The **energy** required to break a string depends on the stress known as tensile failure stress.It is not related to the **length** of the string .for more **knowledge** ref. Mohr’s theory

## Quantum Entanglement Links

- http://cam.qubit.org/articles
- http://cam.qubit.org/node/43
- http://plato.stanford.edu/entries/qt-entangle/
- http://www.wired.com/wiredscience/2011/01/timelike-entanglement/
- http://www.superconsciousness.com/topics/science/what-quantum-entanglement
- http://www.answers.com/topic/quantum-entanglement
- http://calitreview.com/51
- http://en.wikipedia.org/wiki/Quantum_entanglement

## A question from Maths (for Members and Visitors)

Vinolia Maserumule asks:

“Find the relationship between L(the length of the shape L-shape)and S(the number of small squares in the L-shape)P(the perimeter of the L-shape)T(the total number of match sticks). Will 600 match sticks be enough to build a L-shape with sides of 100 squares?”

## What is impact parameter?

**Impact parameter** is the perpendicular distance between the velocity vectors of two objects (considered to take part in a collision) when they are at infinite distance (at such a distance that there is no interaction between the two particles)

**In Rutherford’s alpha scattering experiment,** the gold nucleus is at rest and therefore, in this case

**Impact parameter** is the perpendicular distance between the gold nucleus and the the direction of the velocity vector of alpha particle when the alpha particle is at infinite distance (i.e; the force of interaction between the gold nucleus and the alpha particle is negligibly small)

## Calculating Unknown Mass

Ricardo ,of mass 80 kg , and carmelita , who is lighter , are enjoing lake merced at dusk in a 30 kg canoe . When the canoe is at rest in the placid water ,they exchange seats which are 3m apart and symmetrically located with respect to canoe center . Ricardo notices that canoe moves 40cm relative to submerged log during the exchange and calculate carmelitas mass ,which she has not told him . What is it? (Piyush posted)