Differences

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--- course_planning:computation:scratch_work [2016/03/12 23:03] – [Code] obsniukm
+++ course_planning:computation:scratch_work [2016/03/25 18:40] (current) – [Code] obsniukm
@@ Line 30: / Line 30: @@
 <code python>
 #Objects
-runawaycraft = sphere(pos=vector(-200,400,0), radius=10, color=color.red)
+hovercraft = sphere(pos=vector(-200,400,0), radius=1)
 #Parameters and Initial Conditions
 g = vector(0,-9.81,0)
-runawaycraftm = 1500
+hovercraftm = 1500
-runawaycraftv = vector(53.64,0,0)
+hovercraftv = vector(53.64,0,0)
-runawaycraftp = runawaycraftm*runawaycraftv
+hovercraftp = runawaycraftm*runawaycraftv
 #Time and time step
@@ Line 45: / Line 45: @@
 #MotionMap/Graph
-runawaycraftMotionMap = MotionMap(runawaycraft, tf, 5, markerScale=1, labelMarkerOrder=False, markerColor=color.orange)
+hovercraftMotionMap = MotionMap(hovercraft, tf, 5)
 #Calculation Loop
-while runawaycraft.pos.x < 0:
+while hovercraft.pos.x < 0:
-	rate(500)
+    Fgrav = hovercraftm*g
+    Fground = -Fgrav
+    Fnet = Fgrav + Fground
-	Fgrav = runawaycraftm*g
+    hovercraftp = hovercraftp + Fnet*dt
-	Fground = -Fgrav
+    hovercraft.pos = hovercraft.pos + (hovercraftp/hovercraftm)*dt
-	Fnet = Fgrav + Fground
-	runawaycraftp = runawaycraftp + Fnet*dt
+    hovercraftMotionMap.update(t, hovercraftp/hovercraftm)
-	runawaycraft.pos = runawaycraft.pos + (runawaycraftp/runawaycraftm)*dt
-	runawaycraftMotionMap.update(t, runawaycraftp/runawaycraftm)
+    t = t + dt
-	t = t + dt
 </code>
+<WRAP tip>
+== Tutor Questions ==
+  * **Question:**  What assumptions did you make about the motion of the hovercrafts?
+  * **Expected Answer:**  That the runaway craft has a constant velocity, and the rescue craft starts from rest with a constant acceleration.
+  * **Question:**  Are these velocities and accelerations calculated from the numbers given exact?
+  * **Expected Answer:**  No, these are only average numbers, not instantaneous.  In order to get more "exact" numbers, we would need more data.
+  * **Question:**  Is the predicted position of the rescue craft a good one?
+  * **Expected Answer:**  Not really, basing the trajectory off the first 20 seconds of data is probably not the best -- but it is all we have to work with.
+  * **Questions:**  Can you draw a plot of position vs. time for both crafts?  What are the important features of this graph?
+  * **Expected Answer:**  The point where the two curves cross is when we should jump.  One should be linear, the other quadratic.
+  * **Questions:**  Can you draw a plot of velocity vs. time for both crafts?  What are the important features of this graph?
+  * **Expected Answer:**  The acceleration is the slope of each curve (constant in both cases).
+</WRAP>