According to NASA, re-entry into the atmosphere occurs at 400,000 feet (122 km). The ship would travel through vacuum for about 68h20min. At this point, it would be travelling at just under 11 km/s. I don't think it will reach anything near terminal velocity before crashing or burning up.
I did...
I'm not a sparky, but couldn't the symbol be a variable capacitor symbol (capacitor with a slash through it, like a variable resistor symbol has a slash through it)? That would fit in with it being a voltage-controlled capacitor.
Edit: I think you're exactly right - I found this diagram with an...
The equation does account for the increase in acceleration as the ship gets closer to earth. The equation with constant acceleration would be much simpler.
The gravitational parameter is a combination of the universal gravitational constant, G, and the mass of the earth. It is a constant and...
If you assume the ship starts with zero velocity and falls directly towards the earth, it forms a radial elliptic trajectory:
http://en.wikipedia.org/wiki/Radial_trajectory#Elliptic_trajectory
You can then use the radial Kepler equation to work out the time for it to fall to the centre of...
Surely this is then just another form of perpetual motion machine? In these cases, violations of the second law are often possible once you ignore friction.
This is an incorrect thought experiment since it confuses internal and external forces. Although you are are applying a torque to twist the rod, it's also apply an equal and opposite torque on you. The overall system, consisting of you and the rod experiences no net change.
If you want a very...
That's a cop-out.
I agree, given the simplifying assumptions that have been made here, it's not possible. But then those calculations can be done on the back of an envelope, using generic data from the internet, in less than 30min.
It is possible to accurately calculate or measure the moments...
It doesn't make this assumption. When you've got bodies that are both spinning about their own axes, as well as rotating about some other axis, the toal angular momentum is the sum of the angular momentum due to the spin, as well as that due to motion about the other axis.
In this example...
The energy gets converted to heat, but angular momentum must still be conserved. The angular momentum of the spinning wheels will be converted to rotation of the truck about it's rotation point. Using some very rough numbers:
Moments of inertia:
I_wheel = 18.4 N.m.s^2
I_truck = 23,263...
This part doesn't really depend on the time system in use. It's only based on seconds because we define c in units of m/s.
If we defined c in untis of m/decimal 'second', the definition would then be the distance travelled by light in a vacuum in 1/c decimal 'seconds'.
Back on the bike after a long, work-induced absence.
21 mile Critical Mass ride through central Johannesburg
http://app.strava.com/activities/20581334
17870
I don't think this is right. Most oxygen in the air is in the form of O2 molecules, which I believe are bigger than water molecules. I think N2 and CO2 molecules may also be bigger.
In most cases, water tight refers to liquid water, not gases or water vapour. I think the actual explanation...
Which is, technically, the correct way of doing it: total distance divided by total time.
I'm not sure about mobile apps, but websites such as Garmin Connect and desktop programs like SportTracks will display both average speed and average moving speed. I think SportTracks also lets you...
I feel it somewhat defeats the purpose of a log if you just add a lump sum, rather than logging each ride individually (although perhaps some flexibility for weekly sums could be allowed).
2x 44mile, this weekend and last weekend.
http://app.strava.com/rides/15251521...
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