Calculating Electron Trajectory in a Parallel Plate Conductor

[laurajean997]

Homework Statement

An electron is fired at a speed vo = 5.6 ✕ 10^6 m/s and at an angle θo = -40° between two parallel conducting plates that are D = 2.5 mm apart, as in Figure P16.66. The voltage difference between the plates is ΔV = 103 V.

Homework Equations

F = Eq

E = V/d

a = F/m

The Attempt at a Solution

I tried finding acceleration with (ΔV/D)(q/m) or 103/.0025 * 1.6e-19/9.11e-31

I found Vy with 5.6e6sin(40)

Then i used vyf^2 = vyo^2 + 2aΔy to solve for Δy

then i subtracted my answer from .00125 m and got .54 mm, but the website says I'm off by more than 10%.

I haven't tried part B yet because i could have acceleration wrong and that will just mess up both answers.

 

[maajdl]

Don't forget gravity, or at least check how it compares with the acceleration of the electric field.
Write down equations, instead of narrating your calculations.

 

[laurajean997]

The acceleration was something x 10^15 so i figured gravity was negligible.

 

[gneill]

Homework Statement

An electron is fired at a speed vo = 5.6 ✕ 10^6 m/s and at an angle θo = -40° between two parallel conducting plates that are D = 2.5 mm apart, as in Figure P16.66. The voltage difference between the plates is ΔV = 103 V.

Homework Equations

F = Eq

E = V/d

a = F/m

The Attempt at a Solution

I tried finding acceleration with (ΔV/D)(q/m) or 103/.0025 * 1.6e-19/9.11e-31

I found Vy with 5.6e6sin(40)

Then i used vyf^2 = vyo^2 + 2aΔy to solve for Δy

then i subtracted my answer from .00125 m and got .54 mm, but the website says I'm off by more than 10%.

I haven't tried part B yet because i could have acceleration wrong and that will just mess up both answers.

Hi laurajean997. Welcome to Physics Forums.

Can you show your attempt in a bit more detail? In particular, show the values that you obtained for the intermediate steps.