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--- 183_projects:problem10b_fall2024 [2024/10/28 15:40] – hallstein
+++ 183_projects:problem10b_fall2024 [2024/10/30 21:42] (current) – hallstein
@@ Line 60: / Line 60: @@
 **Part 1: Finding the angle of the platform**
-We would like to increase the angle of the inclined plane so that the block slides off of the plane and into the elevator shaft. Assume the plane is constructed of steel.
+We would like to increase the angle of the inclined plane so the block begins to slide on the plane(ramp). The idea here is we want it to fall into the elevator shaft so you can start the next part. Assume the plane is constructed of steel.
   - Do we want to use static or kinetic friction?
   - Draw a free-body diagram of the block on the inclined plane.
   - Find components of each force parallel and perpendicular to the plane.
-  - In terms of variables, what are the normal force and the frictional force?
+  - In terms of variables, what are the normal and frictional forces?
   - What is the angle of the plane?
-**Part 2: finding the spring compression**
+**Part 2: Finding the energy stored in the spring**
 The most straightforward distance to find is finding the maximum possible distance a harpoon can reach. This will occur when the block is dropped over the greatest distance (from the roof) and launched from the highest elevation (also from the roof). So, let's work with this first.
-  - We want to use the energy principle to find the energy stored in the spring. What are you including in your system include in our system?
+  - We want to use the energy principle to find the energy stored in the spring. What are you including in your system?
   - We'd like to use the simplest model, with this in mind what assumptions can we make to simplify this process?
   - What, if anything does work on your system? If any work is done, calculate this work.
@@ Line 84: / Line 84: @@
 **Part 4: Does it clear the wall?**
   - Does the time of fall of the horizontally-launched harpoon depend on the launch speed?
-  - Is this constant force motion? If so, we can use kinematics here. How much time does it take the harpoon to reach the wall? Again, keep in variables.
+  - Is this constant force motion? If so, we can use kinematics here.
+  - How much time does it take the harpoon to reach the horizontal location of the wall? Again, keep in variables.
   - What is the elevation of the harpoon at the time found in the previous step - now, use your known quantities to get a numerical value. Does it clear the wall?
 **Part 5: What is the range/ total horizontal distance of the launched harpoon?**
-  * Use a similar procedure here as you used in part 4 to find the range.
+  - Use a similar procedure here as you used in part 4 to find the range with a slight modification.
-  *
+  - Start with the vertical direction to find the time it takes the harpoon to reach the level of the zombies (hit the zombie).
+  - Use the horizontal direction and the time from the previous step to get the range.
 **Part 6: Amount of ice**
   - This is the non-review part of this problem.
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 **Post-Solution questions:**
   * A 90 kg zombie is moving 1 m/s directly toward Thunderdome.  If a harpoon launched with the maximum possible velocity strikes this zombie and embeds in the zombie’s flesh, what is the velocity of the zombie immediately after being struck with the harpoon?
-  * Willard suggests you can increase the range of the harpoons if the harpoon launcher is not anchored to the floor, and thereby would recoil.  Would this work?  Use the lowest workable launch speed to confirm your prediction.  What is the new launch speed, and what is the recoil speed of the launcher/support?  The anchor and spring launcher have a mass of 400 kg (excluding the harpoon).
+    * The zombie slides with this velocity and friction causes it to come to a stop. What is the work done by friction during this slide? Also, the coefficients of friction between the zombie and the horizontal surface are $\mu_s = 0.3$ and $\mu_k = 0.2$. How far does the zombie slide before coming to a stop?
-  * Draw a free-body diagram of the harpoon launcher as it slides along the concrete floor. What is the frictional force acting on the launcher during this slide, and using forces how far does it slide.  After all, you don’t want it to fall into the elevator shaft.
+  * Willard suggests you can increase the range of the harpoons if the harpoon launcher is not anchored to the floor, and thereby would recoil.  Would this work?  Check your prediction by calculation.  What is the new launch speed, and what is the recoil speed of the launcher/support?  The anchor and spring launcher have a mass of 400 kg (excluding the harpoon).
+  * Draw a free-body diagram of the harpoon launcher as it slides along the concrete floor. What is the frictional force acting on the launcher during this slide? How far does it slide?  After all, you don’t want it to fall into the elevator shaft.
   * Sketch the trajectory of one of the launched harpoons. For a point halfway from where it is launched to where it strikes a zombie, draw a free-body diagram showing all forces acting on the harpoon. In the past when objects were in freefall, we used a vertical-horizontal coordinate system. Here, we'd like to investigate what the parallel and perpendicular components of the net force look like, and how they affect the motion. With this in mind, sketch the parallel and perpendicular components of the net force acting on the arrow.
@@ Line 111: / Line 115: @@
   * Now, find the minimum distance your defending mechanism can reach and still hit a zombie. If you took our suggestions above and kept everything in variables, this is where you thank us.
+  * What would be the minimum distance of a harpoon if Willard's scheme of not anchoring a launcher were employed?