rename shell.tex to momentum-shell.tex and add momentum-shell.typ typ…

…st translation

add jensens-inequality.typ converted from jensens-inequality.tex

assets/jensens-inequality/jensens-inequality.typ

@@ -0,0 +1,42 @@
+#import "@preview/cetz:0.3.1": canvas, draw
+#import "@preview/cetz-plot:0.1.0": plot
+
+#set page(width: auto, height: auto, margin: 8pt)
+
+#canvas({
+  let mark = (end: "stealth", fill: black, scale: 0.7)
+  draw.set-style(
+    axes: (
+      y: (label: (anchor: "north-west", offset: -0.2), mark: mark),
+      x: (label: (anchor: "south-east", offset: -0.25), mark: mark),
+    ),
+  )
+
+  plot.plot(
+    size: (8, 6),
+    x-label: $x$,
+    y-label: $log x$,
+    y-min: -1,
+    x-tick-step: none,
+    y-tick-step: none,
+    axis-style: "school-book",
+    {
+      // Main logarithmic curve
+      plot.add(
+        style: (stroke: rgb(0%, 0%, 80%) + 1.5pt),
+        domain: (11, 150),
+        samples: 150,
+        x => calc.ln(x - 10) - 2,
+      )
+
+      // Dashed line
+      plot.add(
+        style: (
+          stroke: (paint: orange, thickness: 1.5pt, dash: "dashed"),
+        ),
+        domain: (8, 120),
+        x => 0.2 + (3 - 0.2) * (x - 8) / (120 - 8),
+      )
+    },
+  )
+})

assets/momentum-shell/momentum-shell.typ

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+#import "@preview/cetz:0.3.1": canvas, draw
+
+#set page(width: auto, height: auto, margin: 3pt)
+
+#canvas({
+  import draw: line, content, circle
+
+  let rx = 4
+  let ry = 2.2
+  let arrow-style = (mark: (end: "stealth", fill: black), stroke: 1pt)
+
+  // Axes
+  line((-rx - 0.5, 0), (rx + 0.5, 0), ..arrow-style)
+  content((rx + 0.5, 0), $q_1$, anchor: "west", padding: 2pt)
+
+  line((0, -ry - 0.5), (0, ry + 0.5), ..arrow-style)
+  content((0, ry + 0.5), $q_2$, anchor: "south", padding: 2pt)
+
+  // Ellipse
+  circle(
+    (0, 0),
+    radius: (rx, ry),
+    stroke: blue,
+    fill: rgb(0%, 0%, 100%, 5%),
+    name: "ellipse",
+  )
+
+  // Labels for radii
+  content((rx + .2, 1), $sqrt(2E \/ m)$, anchor: "south-west", padding: 1pt, name: "r1")
+  line((rx, 0), "r1.south", stroke: 0.2pt)
+  content((0.5, ry + .5), $sqrt(2E \/ k)$, anchor: "south-west", padding: 1pt, name: "r2")
+  line((0, ry), "r2.south-west", stroke: 0.2pt)
+
+  // Label P
+  content((3, 1), text(fill: blue)[$P$])
+})