Monthly Archives: February 2019

Homopolar Motorcar

A homopolar motor is a device that relies on flowing electricity, magnetic fields, and the interaction between the two. It consists of a voltage source, neodymium magnets, and a conductor that allows electricity to flow. And it’s super easy to make yourself!

What you’ll need:

  • 1 AA battery
  • 2 neodymium magnets
  • Thick copper wire

 

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Step 1

Place one of your magnets onto the positive terminal of the battery.

Holompolar Motorcar Step 1

Step 2

Use the already attached magnet to test the poles of the second magnet. Figure out which sides are repelling each other, and place the second magnet so that the repelling side faces away from the battery. This way, either both South poles or both North poles are facing outwards! (Note: it doesn’t matter which, as long as they’re consistent with each other!)

Holompolar Motorcar Step 2

Step 3

Shape your copper wire so that it can hook easily on the inside of the magnets. Try to maximize the amount of contact it has with the magnets on BOTH sides, so as much electricity as possible can flow. When it’s been properly shaped, hook the wire onto the motor!

Holompolar Motorcar Step 3

Instead of using a wire, you could use a sheet of aluminum foil! Lay it as flat as you can on a level surface, away from any metals that might attract your magnets. Make sure there are no tears or holes in the aluminum. Then place your battery-magnet motor on top! The aluminum will allow electricity to flow!

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When a magnetic field is applied to an object carrying electricity, it applies a force to that object. This is called the Lorentz Force. Due to the electricity flowing through the magnets, this force becomes a torque, causing the motor to rotate and drive forward!

Homopolar Motorcar Rollin

Written By: Scott Yarbrough

For Mimi by Twin Musicom is licensed under a Creative Commons Attribution license (https://creativecommons.org/licenses/by/4.0/)

Artist: http://www.twinmusicom.org/

What is Escape Velocity?

Escape Velocity is probably something you’ve heard on a TV show, or maybe you learned about it from NASA talking about their newest spacecraft. It is a commonly discussed term, but it isn’t the easiest thing to understand. Imagine you’re in a strange universe where only the Earth exists. The only gravity comes from its center, and it extends infinitely far away, getting weaker and weaker the further away you get. In order to get to that infinite point before you get pulled back by the Earth’s gravity, you need to be going at least 11.2 km/s (25,000 mph). This speed is the escape velocity!

escape velocity 1
This value depends on both the distance from the gravitational center of the object you’re escaping from and the mass of the object. The closer you are to a heavier object, the faster you need to go to reach escape velocity. For example, escape velocity from the Earth at a distance of the moon’s orbit is only 1.3 km/s (3,000 mph), but to escape from the sun’s gravity at the distance of the Earth is a whopping 44.7 km/s (100,000 mph)!

escape velocity moon

But since there’s no such thing as a universe where only the Earth exists, we have to worry about the gravity of other celestial objects! Once you escape from the Earth’s gravity, you’ll then be captured by the sun. If you escape that, then you’ll be captured by the Milky Way’s gravity! So the hypothetical infinite point is just that: hypothetical! No matter what, there’s always going to be something pulling on you with gravity.

Written By: Scott Yarbrough

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We would like to thank you for visiting our blog. AstroCamp is a hands-on physical science program with an emphasis on astronomy and space exploration. Our classes and activities are designed to inspire students toward future success in their academic and personal pursuits. This blog is intended to provide you with up-to-date news and information about our camp programs, as well as current science and astronomical happenings. This blog has been created by our staff who have at least a Bachelors Degree in Physics or Astronomy, however it is not uncommon for them to have a Masters Degree or PhD. We encourage you to also follow us on Facebook, Instagram, Google+, Twitter, and Vine to see even more of our interesting science, space and astronomy information. Feel free to leave comments, questions, or share our blog with others. Please visit www.astrocampschool.org for additional information. Happy Reading!

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