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The total force on charge q on the vertex

Can you please answer the following question?
Consider the charges q,q and -q placed at the vertices of an equilateral triangle. What is the force on each charge?
I actually didn’t understand the total force on charge -q at the vertex C of the equilateral triangle. How is it equal to root3Fn where n is the unit vector along the direction bisecting the angle BCA (Why?).

Thejaswini posted the question


An equilateral triangle. {3/1}
An equilateral triangle. {3/1} (Photo credit: Wikipedia)

Why is it dangerous to stand in the upper deck of a double decker bus?

A modern Ashok Leyland BEST double decker bus

Why is it dangerous to stand in the upper deck of a double decker bus?

Asked Sona

Raja Bhargab Answers:
“a body is said to be more stable when its CENTER OF GRAVITY is kept as low as possible. In a double decker bus , the c.g. of our body is obviously at higher place than the lower deck.In addition , if we stand the c.g. goes the higher , which will lead for a great imballance to be followed by a severe fall off. Moreover,when the bus moves or jerks,in lower deck,the moment of deflecting force is tolerable . But in the upper deck,it’s tremendously high”
A double-decker bus plying in the 122 route fr...

What physical phenomenon is there that a black hole has a high gravity?

What physical phenomenon is there that a black holehas a high gravity?

Simulated gravitational lensing (black hole go...
Simulated gravitational lensing (black hole going past a background galaxy). (Photo credit: Wikipedia)

Sona asked

Heat! Heat! Heat!

Thermal vibration of a segment of protein alph...
Thermal vibration of a segment of protein alpha helix. The amplitude of the vibrations increases with temperature. (Photo credit: Wikipedia)

A glass ball at -10 degrees C is placed in 500 ml of water at 20 degrees C. The final temp is 15 degrees C.
A. How much heat is lost by the water
B. what is the heat capacity of the water
C. How much heat is gained by the glass ball
D. What is the heat capacity of the glass ball
E. what is the ratio of the heat capacities of the water and the glass ball
F. What is the ratio of the temp changes of the water and glass ball
G. How are the answers to e and f related

Difference between Dielectric Break Down and Corona Discharge


Asked Deepika

  • Corona (egrejeen.wordpress.com)

Photon and Antiphoton

Photon soup

I heard that photon is its own antiparticle. If so, what is the different between these two photons

Asked Thatoekhant

Photon's Castle - fantastical sculpted fun!


Photons also have their antiparticles, but antiphotons are photons themselves.

The following links will help you know the matter in details.





Conversion of Galvanometer to Ammeter problem

Diagram of D'Arsonval/Weston type galvanometer.
Diagram of D'Arsonval/Weston type galvanometer. (Photo credit: Wikipedia)

A galvanometer can be converted to ammeter by connecting a low resistance, called shunt in parallel with it. If a galvanometer of resistance 45 Ω is shunted by a resistance of 5 Ω what fraction of main current passes through the  Galvanometer? What is the current which flows through the shunt?


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