Quote:
Originally Posted by Turtle
Here again I point out these specific instructions mention the car should be able to coast once the weight is down, so my thinking is to reach top speed just as the string comes off the drive cone and then you get the best coast distance.
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Quote:
Originally Posted by arkain101
Aha. but how fast will the car get moving? And, thus we ask, how far will it coast after the weight has stopped pulling?
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That's what the link I posted speaks to. If you're going for distance it's less efficient to deliver the energy quickly gaining high speed then letting it coast than to deliver the power over a long time never gaining much speed and never 'coasting'.
The total energy is the same in either case, but at high speeds there's more air resistance and friction from the moving parts of the car. So, slow speed and low power for a long duration is conventional wisdom when going for
speed [EDIT: distance].
Quote:
Slow Moving vs. Fast Moving mouse trap vehicle Here are my thoughts on the ultimate distance vehicle. In sharing my thoughts with you please understand that I am not telling you how to build the perfect Distance Car but I am pointing out the application of physics as I applied it to my mousetrap powered vehicles. I tend to design my distance cars to travel extremely slow. One of my cars that travels 100 meters or more may take over 5 minutes to travel that distance. My idea is to reduce the power output to a minimum, only supplying enough energy to the vehicle to overcome the friction. By traveling slowly you will reduce the air resistance to a minimum vs. a fast traveling car that will have more air friction acting against it. Also, I feel that a quick accelerating car will create more heat energy during a quick acceleration than a slow accelerating vehicle which will reduce the energy needed to travel a great distance. Building a mouse trap car for distance means minimizing the wasted energy and converting more energy into displacement of the vehicle. With that in mind, I like to build cars that have very low frictional forces acting against them and move slowly. I try to find a harmonious balance between the movement of my vehicle and the length of the lever arm. My cars tend to have long lever arms and large wheels. If a lever arm is too long the vehicle will not travel the full distance because you must have enough torque to keep the car going and the torque changes with spring angle.
Your ultimate source for mousetrap powered cars and vehicles
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~modest
