class_materials/exercises/particle_update_position.ipynb

@@ -52,17 +52,18 @@
    ],
    "source": [
     "class Particle:\n",
-    "    def __init__(self, mass, velocity):\n",
+    "    def __init__(self, mass, velocity, position):\n",
     "        self.mass = mass\n",
     "        self.velocity = velocity\n",
+    "        self.position = position\n",
     "\n",
     "    def momentum(self):\n",
     "        return self.mass * self.velocity\n",
     "\n",
-    "    def update_position(self, position, dt):\n",
-    "        return position + self.velocity * dt\n",
+    "    def update_position(self, dt):\n",
+    "        return self.position + self.velocity * dt\n",
     "\n",
-    "particle = Particle(mass=2.1, velocity=0.8)\n",
+    "particle = Particle(mass=2.1, velocity=0.8, position = 8.2)\n",
     "print(particle.momentum())"
    ]
   },
@@ -80,7 +81,7 @@
     }
    ],
    "source": [
-    "position = 8.2\n",
+    "\n",
     "new_position = particle.update_position(position, dt=0.1)\n",
     "print(new_position)"
    ]