Electric physics?

Question

A proton accelerates from rest in a uniform
electric field of 678 N/C. At some time later,
its speed is 2.2 x10^6 m/s.
What is the magnitude of the acceleration
of the proton?

How long does it take the proton to reach this
speed

How far has it moved in this time interval

Answer 1

F = qE = ma ──► a = qE / m
a = (1.6x10^-19 C)(678 N/C) / (1.67x10^-27 kg)
= 6.5x10^10 m/s²

The rest is just kinematics:
Know: v0, v, a
Want: t
Use: a = (v - v0)/t ──► t = (v - v0)/a
t = (2.2x10^6 m/s)/(6.5x10^10 m/s²) = 3.4x10^-5 s

Know: v0, a, t
Want: d
Use: d = v0·t + ½a·t²
d = ½(6.5x10^10 m/s²)(3.4x10^-5 s)²
= 38 m

Answer 2

And you need to know that the mass of a proton is
1.672X1-^(-27) kg

Doug

Answer 3

hell if i know