Our Reaction is Kind of Like This:

1
Our Reaction is Kind of Like This
Imagine a bug flying very fast and theres a
garbage truck sitting there that our bug crashes
into!!! Oddly enough, the bug and garbage
truck are gone a dump truck small electric car
appear in the wake And they drive off into the
sunset!
Make Sense!?
2
Unlikely but if it did happen, what physics
rules must be followed?

• Conservation of momentum (pbefore pafter).
• Conservation of energy (KEBUG KEdump KEcar).
• 2A. Conservation of energy mass (E mc2).

3
Conservation of Momentum Restrictions
For each axis pbefore
pafter pbug pgarbage pdump pcar
4
Momentum Before the Collision
A 0.0001 kg bug is flying at a speed approaching
light speed (3.0 x 108 m/s) and crashes head on
into a 16,000 kg garbage truck at rest.
In the axis of the bugs motion.
The truck is not moving. This term 0.
pbefore pbug pgarbage
pbefore (mv)bug (mv)garbage
pbefore 0.0001kg(3 x 108 m/s) 0
pbefore 30,000 kg.m/s
5
Momentum After the Collision
Initial System Momentum
(py) truck
(px) truck
p 30,000 kg.m/s x-axis only
(px) car
(py) car
(px)car (px)dump 30,000 kg.m/s
(py)car (py)truck 0 kg.m/s
6
What changes if

• the garbage truck idles and randomly rocks back
  and forth before the collision?

• Initial py varies moment to moment.
• Typically, the initial py ? 0 kg.m/s.
• After collision y-axis momenta wont cancel.

7
Our Reaction is Really More Like The Simulated
Model Below
neutrino neutron ? proton muon
nm n0 ? p m-
udd
uud
8
which is in 3-D!
Lets welcome the z-axis.
An extra dimension of space
an extra dimension of FUN!
Neutron at Rest
(pz)n (pz)n (pz)p (pz)m
(px)n (px)n (px)p (px)m
(py)n (py)n (py)p (py)m