- #1

Vanessa Avila

- 94

- 1

## Homework Statement

In the figure, a proton, mass 1.67×10^−27 kg, is projected horizontally midway between two parallel plates that are separated by 0.20cm, with an electrical field with magnitude 7.8×10^5N/C between the plates. If the plates are 5.40cm long, find the minimum speed of the proton that just misses the lower plate as it emerges from the field.

## Homework Equations

q(E) = ma

x = vt

y = 1/2a(t^2)

## The Attempt at a Solution

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This is what I did:

1.6*10^-19(7.8*10^5) = 1.67*10^-27 (a)

solving for

*a*I get: 7.47*10^13 m/s^2

then i solve for t

2*10^-3 = (1/2)(7.47*10^13)(t^2)

t = sqrt(7.47*10^13/((2)(2*10^-3))

I get 7.32*10^-9 s

then i plug that in the x = vt eqn

0.054/7.23*10^-9 = v

v = 7.4*10^6 m/s

But that is wrong