My son usually won this race because I taught him about Newton's 2nd law of rotary motion; viz, angular acceleration equals applied torque divided by moment of inertia. Since the torque applied to the wheels is constant (it depends on the inclination angle of the track), their angular acceleration will be greater when their moment of inertia is smaller. So the fastest racers always have wheels with minimal moment of inertia. This means keep the majority of each wheel's total weight as close to the axle as you can. They could be spoked wheels with light weight rims and tires or disk wheels made of balsa glued to a pine hub.
It appears that some of you are confusing temperature with heat. A substance can have a very high temperature but not be able to melt shit unless it also contains enough heat.
All substances have a property called specific heat capacity. This is the amount of heat input required to raise the temperature of a unit mass of the substance by one degree. Metals have a fairly low value of specific heat capacity -- water has an unusually high value.
The temperature of the sun's corona, for example, is over one million degrees but you could probably stick your hand in it without getting burned. It is such a low density plasma that it simply doesn't contain much heat.
Magma's temperature is around 700 - 1000 degrees C. As I wrote in a previous message, there are plenty of elements and inorganic compounds that have higher melting points.
When the magma is exposed to the atmosphere (by the way, it is called lava when it reaches the surface), its temperature drops because it transfers a lot of its heat to the air and anything else nearby.
The bottom line is, the plan to drill into a magma vent is not a big deal, not difficult to do, and not threatening to life on Earth.
Hold on thar, pardner. A great many elements and inorganic compounds have melting points higher than magma. Granitic rocks melt at about 750 degrees C, basaltic rocks at about 1000 degrees C.
Pure iron, for example, melts at 1535 degrees C; magnesium at 1656 degrees; tungsten at 1660 degrees; and uranium at 3410, the highest melting point of any element.
Perhaps it's not as wimpy as you think, Brian. It's not a $3000 electric scooter; it's a $5000 electric scooter. Check on http://www.amazon.com/exec/obidos/tg/detail/-/ B000 07EPJ6/ref=segway_tn_left/104-2314726-5360741.
I'm one of an unknown but large number of technology literate folks who want one (see http://news.com.com/2100-1040-978789.html?ta g=fd_t op), with a PhD in physics and a 40-year career in systems engineering.
I agree that it's price will fall as it becomes more visible on the nation's sidewalks. But it'll be quite a while before it drops to $500.
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My son usually won this race because I taught him about Newton's 2nd law of rotary motion; viz, angular acceleration equals applied torque divided by moment of inertia. Since the torque applied to the wheels is constant (it depends on the inclination angle of the track), their angular acceleration will be greater when their moment of inertia is smaller. So the fastest racers always have wheels with minimal moment of inertia. This means keep the majority of each wheel's total weight as close to the axle as you can. They could be spoked wheels with light weight rims and tires or disk wheels made of balsa glued to a pine hub.
It appears that some of you are confusing temperature with heat. A substance can have a very high temperature but not be able to melt shit unless it also contains enough heat.
All substances have a property called specific heat capacity. This is the amount of heat input required to raise the temperature of a unit mass of the substance by one degree. Metals have a fairly low value of specific heat capacity -- water has an unusually high value.
The temperature of the sun's corona, for example, is over one million degrees but you could probably stick your hand in it without getting burned. It is such a low density plasma that it simply doesn't contain much heat.
Magma's temperature is around 700 - 1000 degrees C. As I wrote in a previous message, there are plenty of elements and inorganic compounds that have higher melting points.
When the magma is exposed to the atmosphere (by the way, it is called lava when it reaches the surface), its temperature drops because it transfers a lot of its heat to the air and anything else nearby.
The bottom line is, the plan to drill into a magma vent is not a big deal, not difficult to do, and not threatening to life on Earth.
Hold on thar, pardner. A great many elements and inorganic compounds have melting points higher than magma. Granitic rocks melt at about 750 degrees C, basaltic rocks at about 1000 degrees C. Pure iron, for example, melts at 1535 degrees C; magnesium at 1656 degrees; tungsten at 1660 degrees; and uranium at 3410, the highest melting point of any element.
Perhaps it's not as wimpy as you think, Brian. It's not a $3000 electric scooter; it's a $5000 electric scooter. Check on/ B000 07EPJ6/ref=segway_tn_left/104-2314726-5360741.
a g=fd_t op), with a PhD in physics and a 40-year career in systems engineering.
http://www.amazon.com/exec/obidos/tg/detail/-
I'm one of an unknown but large number of technology literate folks who want one (see
http://news.com.com/2100-1040-978789.html?t
I agree that it's price will fall as it becomes more visible on the nation's sidewalks. But it'll be quite a while before it drops to $500.
We'll really miss you as we glide around town.