(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

An α (Alpha) particle consists of two neutrons and two protons bound together into a single particle with a charge of +2e. We normally measure the kinetic energy of such particles in millions "electron volts" or MeV. (1 eV = 1.6 X 10-19J).

Assume a steady stream of α particles travels with a constant energy of 20 MeV and carries a current of 2 μA.

a) If the beam is directed perpendicular to a plane target, how many α's will strike this target in 5 seconds?

b) At any given instant, how many α's are in a 15 cm length of the beam?

c) Through what electrical potential diffence [sic] is it necessary to accelerate each α from rest to bring it to the energy of 20 MeV?

2. Relevant equations

v = ir

r = p*l/a

E = .5*mv^2

3. The attempt at a solution

I have the velocity of the particles.

But I don't know how many particles go through a point in 1 second.

if I can get a, b falls in to place.

but I have no idea how to start c

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# Homework Help: Current from stream of particles

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