# Exercise 9: A bit more physics 
**(15 minutes)**

Assuming a relativistic particle, the measured energy of the particle in
our example n-tuple is given by

:::{math}
E_{meas}^{2} = p_{x}^{2} + p_{y}^{2} + p_{z}^{2}
:::

and the energy lost by the particle is given by

:::{math}
E_{loss} = E_{beam} - E_{meas}
:::

Create a new analysis macro (or revise one of the ones you've got) to
make a scatterplot of
$E_{loss}$
vs. **`zv`**. Is there a relationship
between the z-distance traveled in the target and the amount of energy
lost?

:::{figure-md} revolutionary-fig
:class: align-center

<img src="https://imgs.xkcd.com/comics/revolutionary.png" alt="xkcd revolutionary" width="80%">

<https://xkcd.com/675/> by Randall Munroe
:::