This section lists all blog posts, regardless of topic.
How far could you long jump on the moon? 88 feet?March 3, 2008
  | On earth, people are able to long jump roughly 30 feet = 9 meters |
| How far a person can jump is a combination of how fast they are running when they leave the ground and how long they are in the air. |
| How long they are in the air depends on how high they jump |
| Said differently, the higher a person jumps, the longer they are in the air, and thus the further their forward speed caries them |
| I looked up some footage of the olympics on Google Video and it appears that jumpers are airborn for about 0.8 seconds |
| 9 metres / 0.8 seconds = 11.25 metres / second = 40 km/h. This speed feels a bit high to me, so perhaps they are airborn for longer than 0.8 seconds, but we can make a reasonable estimation using this figure. |
| How high do they jump? |
2*t = 0.8 (The total time airborn)
t = 0.4 (The time taken to fall from maximal height)
t = sqrt( 2 * d / 9.8 )
t^2 = 2*d / 9.8
d = ( 9.8 * t*t ) / 2
= ( 9.8 * 0.4*0.4 ) / 2
= 0.784 metres (2.57 feet) |
|
| How fast are they moving upward when they leave the ground? |
v = t * a
= 0.4 * 9.8
= 3.92 metres/second = 14 km/h |
|
| The force of gravity on the moon is 1/6th that of Earth's |
| 9.8 / 6 = approx 1.63 m/s/s |
| How long would it take a jumper to reach their apex if they jumped upward at 3.92 m/s on the moon? |
t = v / g
= 3.92 / 1.63
= 2.4 s |
|
| How high would they go if they jumped upward at 3.92 m/s on the moon? |
d = ( 1.63 * t*t ) / 2
= ( 1.63 * 2.4*2.4 ) / 2
= 4.7 metres = 15 feet (!) |
|
| In conclusion, how far, approximately, could a person jump on the moon given a 40 km/h running speed and 2.4s of air time? |
d = v * t
= 11.25 m/s * 2.4 s
= 27 meters
= 88 feet |
|
First person to drive around the moon and other assorted funMarch 3, 2008
Although it's a little unclear whether the Bush administration's plan to return mankind to the moon will come to fruition, I think we all know that at some point it's inevitable. One of the more obvious developments is an extended stay there, perhaps several months at a time. And when you think of people being on a moon/planet, needing to move from one place to another is important just like it is on earth. I wonder when the first road will be laid on the moon. Looking forward a little further, I find it cute to think of the first person or team to strike out driving across the whole circumference of the moon. That would be quite a historic accomplishment -- and I expect it will be done long before there is a road around the moon. 10,000 km. That's a long, dusty drive. Here are some other interesting future events to consider relating to the moon:
| First person to be buried on the moon |
| New games invented by people on the moon to take the lessened gravity into account |
| First baby born on the moon (I expect that pregnant women will return to earth to have their babies, but eventually I could see this being done) |
| World records that pertain to things done on the moon. Maybe they'd be called "Moon records" since their not really "World" records. I could see long jump being a good one. (Obviously this would require the development of space suits that are much less restrictive) It would be fun to make a mathematical model to predict what the limits of human long jump would be on the Moon. |
UPDATE: Hey cool,
this article isn't too far off what I'm pondering here.
netfirmsMarch 3, 2008
Last Saturday my web hosting provider
netfirms had an outage that lasted quite a while. Once their site (and mine) was back up, it became apparent that the database that I use as my content management system had been corrupted and lost about a year and a half of data. Great.
But wait, netfirms advertises on their website that all of there web service plans are protected by database backups. Fantastic!
Or so you would think. I have phoned them about 5 times, sent email, etc, and each time I'm told that they don't offer database restoration as a service and if they're able to help me it will take a long time because they don't have a "process" in place. Wow. You advertise database backups, but you don't have a "process" in place to restore those databases.
What a bunch of hoo-ey!
UPDATE: On May 1, netfirms finally restored the backup copy of my database. What a sigh of relief.
UPDATE: As of April 3, 2008, I have filed a complaint with the Better Business Bureau. It has been 1 month since the situation and Netfirms' has refused to correct their advertising to accurately reflect the services they provide. I've never submitted a complaint before, so this will be an interesting process.
older >>
