How Do You Calculate Net Force in Coulomb's Law?

[joe98]

Help with coulumbs Law!

Homework Statement

Consider two point charges located on the x axis: one charge, = -10.0 C, is located at = -1.700m ; the second charge, = 30.5C , is at the origin .

What is the net force exerted by these two charges on a third charge = 52.5C placed between and at = -1.055m ?

Your answer may be positive or negative, depending on the direction of the force.

Homework Equations

Coulomb's law

The Attempt at a Solution

first i found,
F(1on3)=k*10*10^-9*30.5*10^-9/.645^2 then,
F(2on3)=k*52.5*10^-9*-10*10^-9/1.055^2

then i added them , but i am gettin the wrong answer d answer shud be -2.43*10^-5 N

can u tell me what's wrong with my working :)

 

[joe98]

the charge is in nC

 

[Clever-Name]

Look at the charges you're using on F(2on3)

 

[joe98]

oh i see thnks :)

 

[rwisz]

I would suggest checking your calculations and units carefully. It is important to use the correct units for charge (Coulombs) and distance (meters) in the equation for Coulomb's law. Also, make sure to include the direction of the forces when adding them together. It may also be helpful to draw a diagram and label the forces to ensure they are added correctly. If you are still getting the wrong answer, try checking your equation and make sure you are using the correct values for the charges and distances.