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Edwardo_Elric
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Homework Statement
Canadian nuclear reactors use heavy water moderators in which elastic collisions occur between neutrons and deuterons of mass 2.0u.
a.) What is the speed of a neutron expressed as a fraction of its original speed, after a head-on elastic collision with a deuteron which is initially at rest?
b.) What is its kinetic energy, expressed as a fraction of its original kinetic energy?
c.) How many such successive collisions will reduce the speed of a neutron to 1/6600 of its original value?
Homework Equations
If the 2nd particle is at rest
[tex]V_{A} = \frac{m_{A} - m_{B}}{m_{A}+m_{B}}[/tex]* V2
[tex]V_{B} = \frac{2m_{A}}{m_{A} + m_{B}}[/tex]* V2
The Attempt at a Solution
let n = neutrons , dn = deuterons
a.)
VnMn = MnVn2 + MdnVdn2
using equation above:
[tex]V_{n2} = \frac{2.0u - 2.0u}{2.0u+2.0u} V_{n}[/tex]
Vn2 = 0
b.) K2 = ?
since Vn2 =0
VnMn = Vdn2
K2 = 1/2 (2.0u)(Vdn2)2
K2 = u(Vdn2)^2 <<<< K equals velocity of deuterons squared times u
c.) (2.0)(1/6600Vn) =
3300 collisions
I honestly don't know about this
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