Colliding Particles using energy

  • Thread starter Thread starter seto6
  • Start date Start date
  • Tags Tags
    Energy Particles
Join the discussion
Ask a follow-up here, or get your own question answered by working scientists, mathematicians and engineers — people, not an autocomplete.
Real named experts · corrections over time · the nuance an AI answer skips
5 replies · 4K views
seto6
Messages
248
Reaction score
0
this question is from my previous assignment which was due 2 weeks back. just revising for mid-term not sure how to solve it. if someone explains it thoroughly it would be grate

Homework Statement


An alpha particle is a nucleus of Helium. It has twice the charge and four times the mass of the proton.

A proton and an alpha particle headed directly toward each other, had each initial speed of 3.9×10−3 c when they were far away.

Here, as is customary when describing processes involving nuclear targets, the speed is expressed as a fraction of c, the speed of light.

What is the distance of closest approach between the proton and the alpha particle?

Hint: There are two conserved quantities. Make use of both.



Homework Equations


U=Eqd or KqQ/r
K=1/2*(mv^2)

The Attempt at a Solution



.5m(v_i)^2 + Eq(d_i)= .5m(v_f)^2 + Eq(d_f)

where (V_f)=0 then i solved for (d_f)
and got the 1.87*10^-27 but the answer should be d_f=1.3*10^-13

could some 1 explain this to me and the reasoning! please
 
Last edited:
Physics news on Phys.org
You are assuming that V_f = 0. Make use of the hint that you were given.
 
this question is from my previous assignment which was due 2 weeks back. just revising for mid-term not sure how to solve it. if someone explains it thoroughly it would be grate
 
v_f is the final velocity , at minimum distance it can reach it will be zero.no?
 
seto6 said:
v_f is the final velocity , at minimum distance it can reach it will be zero.no?
No it won't. Use the hint that the problem gave you! What else is conserved besides energy?