# Find the electric field at the point P on a right triangle

• ino
In summary, the problem asks for the electric field at point P of a right triangle, with three equal charges placed at the vertices and angles of 90°, 45°, and 45°. By considering the net field due to two of the charges, it can be determined that the electric field at point P is given by E = k Q2 / r^2, where r is the distance between the charge Q2 and point P.
ino

## Homework Statement

https://www.physicsforums.com/threads/find-the-electric-field-in-the-point-p-of-a-right-triangle.965285/#post-6125768 knowing that the three charges are equal and that the angles of the triangle are 90°, 45°, 45°.

## The Attempt at a Solution

I tried solving it by calculating the total force on each charge, decomposing it

on the X and Y axis and calculating then the total force acting on P. But I'm not sure if it is correct:

#### Attachments

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Welcome to the PF.

First, if the charges Q1, Q2 and Q3 are all the same, and the point P is equidistant between Q1 and Q3, what can you say about the net electric field at P due to those two charges?

Second, the problem is asking for the E-field at P, not the net force. Can you write the simplified equation for the E-field at point P now that you've thought about the net field from Q1 and Q3?

I am mystified by your working. You seem to be calculating forces between the three charges. These have nothing to do with the question asked.

berkeman
berkeman said:
Welcome to the PF.

First, if the charges Q1, Q2 and Q3 are all the same, and the point P is equidistant between Q1 and Q3, what can you say about the net electric field at P due to those two charges?

Second, the problem is asking for the E-field at P, not the net force. Can you write the simplified equation for the E-field at point P now that you've thought about the net field from Q1 and Q3?

The net field due to Q1 and Q3 is 0; so the electric field will be E = k Q2 / r^2, where r is the distance between Q2 and P.
Is it correct?

berkeman
ino said:
The net field due to Q1 and Q3 is 0; so the electric field will be E = k Q2 / r^2, where r is the distance between Q2 and P.
Is it correct?
Right.

ino said:
so the electric field will be E = k Q2 / r^2, where r is the distance between Q2 and P.
Correct. Now all you have left to do is express r in terms of the given distance d.

## What is an electric field?

The electric field is a physical quantity that describes the strength and direction of the force experienced by a charged particle in an electric field. It is created by the presence of electric charges and is represented by the symbol "E".

## How is the electric field calculated?

The electric field at a point is calculated by dividing the force experienced by a test charge at that point by the magnitude of the test charge. This can be represented mathematically as E = F/q, where E is the electric field, F is the force, and q is the test charge.

## What is a right triangle?

A right triangle is a triangle with one angle measuring 90 degrees. It is one of the basic shapes in geometry and is commonly used in various mathematical and scientific calculations.

## How do you find the electric field at a point on a right triangle?

To find the electric field at a point on a right triangle, we need to consider the contributions of the electric fields from each side of the triangle. This can be done by using the principle of superposition, which states that the total electric field at a point is the vector sum of the individual electric fields from each source.

## What factors can affect the electric field at a point on a right triangle?

The electric field at a point on a right triangle can be affected by various factors, such as the magnitude and direction of the charges on the triangle, the distance of the point from the charges, and the presence of any other nearby charges or objects that may alter the electric field.

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