184_projects:f20_project_9

Dr. McPaddel woke up to a great surprise this morning when she walked outside to admire the junkyard and noticed a mysterious glowing creature stuck to her magnetic crane. Apparently, in all the excitement of showing the contraption to her neighbors, she had forgotten to turn off the machine. The creature had wandered into the scrapyard overnight looking for some metal to eat, and when it wandered near the crane, the metal became magnetized and pulled the creature up into the air, where it remained stuck until Dr. McPaddel discovered it this morning. She alerted the authorities, but it was the Hawkion researchers who arrived before anyone else, to transport the creature to a research facility to learn more about it. They are thinking these animals might be responsible for the disappearance of fish from the lake and green-bellied canaries from the cliffside.

By the time you learn of all this, the creature is already at the research facility. You arrive and the scientists fill you in. They have acquired this beast to study it, but by now they have figured out Dr. McPaddel's crane snagged a young version of the monster. Because of the apparent resemblance to both boars and tigers and their electromagnetic glow the scientists at the compound have taken to calling the monsters EM-boar tigers. So you have captured an EM-boar tiger cub. It turns out that EM boar tigers are super protective of their young and they have organized to attack the Lakeview compound. Surprisingly, even though it is a government facility, there are no guns at the compound. But you are scientists and engineers godammit! You indicate that maybe capturing this new 'alien' species young might have upset the creatures and make a plan to return the beast but you need a distraction to get the cub close enough to give back to its kin.

You decide to construct makeshift launcher that is using magnetic force to launch projectiles so that they will leave the launcher at a speed of $300m/s$. You must construct your launcher on the floor of the laboratory and position it at an angle of 63 degrees so that it is firing out of the window of the laboratory.

At your disposal to construct your launcher, you have access to two copper rails that can be cut to your specifications. You also have perspex that you can cut to any dimensions and chunks of aluminum that can be cut to any shape. You also have access to multiple variable power supplies that can be set to a requested current and a bunch of wires that can be cut to any length and some switches. You must outline your design, explaining the physics behind the design of the magnetic force launcher and indicating the current needed to reach an exit velocity from the launcher of $300m/s$.

caged.jpg

Learning Goals

  • Understand how superposition of magnetic fields works and practice adding magnetic fields together
  • Relate magnetic fields to forces and use those forces to calculate motion
  • Review some basic kinematics concepts
  • Practice building complex models using assumptions and approximations to simplify

Thanks to the research that folks at the Hawkion facility were able to do on the EM-boar tigers, the people of Lakeview have been able to set up a scientifically supported protection system. The research team has found that magnetic fields repel the EM-boar tigers. They have installed a giant magnet into the cliffs nearby, and it is aligned in such a way that there is a constant (practically speaking) $5 \text{ mT}$ magnetic field directed into the ground near Lakeview and the surrounding area. The hope is that the field will ward off the EM-boar tigers and keep the people of Lakeview safe.

However, the scientists of Lakeview are concerned that such a big magnetic field will interfere with their detectors and experiments. In particular, there is a small section of wire (~15 cm) that needs to carry a large amount current (10 - 14 A). The scientists are worried about the force that will be exerted on that high current wire. They've provided the picture below of their lab set up and have asked for your help with two things. First, they would like to know what kind of force they should expect on their high current wire. Second, they have asked for your design of how you would make the net force zero on the high current wire. They said they will happily provide wire(s) of any length, they can adjust the current to whatever you need, and they can position any of the wires as needed. You should outline a design (including a figure with labels) and demonstrate how that makes the net force zero on the high current wire.

Remember, a good solution includes explanations, diagrams, evaluations, and commentary in addition to your calculations. See the Project Write Up Rubric for more details.

Learning Goals

  • Calculate magnetic force on a current carrying wire (including magnitude and direction)
  • Calculate the net force on a wire and determine relative size/direction of forces.
  • Justify the direction of magnetic force and magnetic field using the right hand rule.
  • Explain how magnetic force and magnetic field are related.
  • 184_projects/f20_project_9.txt
  • Last modified: 2020/11/12 22:02
  • by cookkai3