Calculating Force (magnitude and direction) on a proton

[Obama]

Homework Statement

Diagram shows the separations of a proton, electron, and α particle (charge +2e). What is the force (magnitude and direction) on the proton?

Homework Equations

Addition of vectors, Coulomb's law

The Attempt at a Solution

I keep getting 82 degrees but the answer is 68 degrees below the x axis

 

[gneill]

Homework Statement

Diagram shows the separations of a proton, electron, and α particle (charge +2e). What is the force (magnitude and direction) on the proton?

Homework Equations

Addition of vectors, Coulomb's law

The Attempt at a Solution

I keep getting 82 degrees but the answer is 68 degrees below the x axis

It would help if you labelled each of the particles on the diagram, but I suppose we can work out what each of them must be from your desired result

If you show your work, perhaps we can see where the its going wrong.

 

[Obama]

Sorry about that! Was basing it off memory lol.

okay so i found the force between the charge of positive 2 and the proton to be 2.1e-8 N, and i found the other force to be 3.5e-8 N. then i found the x and y components of the forces, and that was 3.4e-8 and 7e-9, respectively. i then added this to the x component of the first force (since there was so y) and found the angle that they create to be 82 degrees, which is incorrect

 

[gneill]

Sorry about that! Was basing it off memory lol.

okay so i found the force between the charge of positive 2 and the proton to be 2.1e-8 N, and i found the other force to be 3.5e-8 N. then i found the x and y components of the forces, and that was 3.4e-8 and 7e-9, respectively. i then added this to the x component of the first force (since there was so y) and found the angle that they create to be 82 degrees, which is incorrect

How did you calculate the x and y components of the second force? It looks like you've interchanged them. Take a look at your diagram; you should be able to estimate the relative sizes of the x and y components of a given force.