Question

What is the difference in finding magnitude of a force on a charge and finding the net electric force acting on a charge?

If given three charges set at a certain places set on a triangle, how would you find the magnitude of a force on one of the charges? Please create a simple example and show each step clearly and explanation for what to do in each step esecially on how to find, set up, and use the components to add the forces together and determine the vector sum of forces.

If given four charges set at a certain places set on a square, how would you find the magnitude of a force on one of the charges? Please create a simple example and show each step clearly and explanation for what to do in each step esecially on how to find, set up, and use the components to add the forces together and determine the vector sum of forces.

If an electron is moving at a certain speed and at a certain angle to a magnetic field, how do I find the force of that electron? Please give me the equation and the rearranged eqation for finding the answer. Please tell me what each letter of the equation stands for and their units. Please create a simple example and take me step by step on how to solve and include the final units of the answer.

Answer 1

force on a charge by another charge is calculated using coulomb's law which is given as

F = k q₁ q₂/r² where q₁, q₂ = magnitude of charges, r = distance between the charges

net force is calculated by taking the vector sum of all the force acting on the charge.

for triangle :

consider an equlateral triangle where q₁, q₂, and q₃ are all positive charges.

step 1 : calculate the force by charge q₂ and q₃ using coulomb's law. and then draw the forces F₂ and F₃ using arrows.

Step 2: Draw horizontal and vertical components of F₂ and F₃ .

Step 3 : take the sum of X-components of F₂ and F₃ to determine net force F_x in horizontal direction

Step 4:  take the sum of Y-components of F₂ and F₃ to determine net force F_y in vertical direction.

Step 5 : Using pythagorean theorem , calculate the net force using the value of F_x and F_y .

for square :

consider a square where q₁, q₂, q₃ and q₄ are all positive charges and are on the four corners of the square.

step 1 : calculate the force by charge q₁ , q₂ and q₃ on charge q₄ using coulomb's law. and then draw the forces F₁ , F₂ and F₃ using arrows.

Step 2: Draw horizontal and vertical components of force F₂

Step 3 : take the sum of forces in X-direction to get net force is X-direction as F_x .

Step 4:  take the sum of forces in Y-direction to get net force in Y-direction as F_y.

Step 5 : Using pythagorean theorem , calculate the net force using the value of F_x and F_y .