Answer:
a)
b)
c)
Explanation:
We use the definition of a electric field produced by a point charge:

<u>a)Electric Field due to the alpha particle:</u>

<u>b)Electric Field due to electron:</u>

<u>c)Electric Force on the alpha particle, on the electron:</u>
The alpha particle and electron feel the same force but with opposite direction:

A force over distance is work the unite is joules
Answer:
83.67 m/s
Explanation:
Set up a calculation to convert units of measure to what you need.
You have km/s and you need m/s.
4.08km 1000 m 83.67m
----------- X ---------- = --------------- the km will cancel out and you are left
12.0 s 1 km s with m/s