search results matching tag: v2

» channel: nordic

go advanced with your query
Search took 0.000 seconds

    Videos (66)     Sift Talk (15)     Blogs (8)     Comments (162)   

4 Revolutionary Riddles

ChaosEngine says...

This line is incorrect Vavg = (V1+V2)/2. That only applies if you run at V1 and V2 FOR THE SAME AMOUNT OF TIME.

Speed is Distance divided by Time, so the formula for calculating average speed is Dtotal / Ttotal.

The problem is that that only works if your second lap can be longer than the first lap.

If they are the same distance, the maths are undefined.

V1 = D1/T1
V2 = D2/T2

Vavg = (D1+D2)/(T1+T2)
if (D1 = D2) then
Vavg = 2D1/(T1+T2)

if Vavg = 2V1 then
2D1/T1 = 2D1/(T1+T2)
then T2 = 0

therefore V2 = D1/0 .... cannot divide by 0 (and no, it's not infinity )

Digitalfiend said:

The track question seems really straightforward. The question is how fast do you have to run the 2nd lap such that the average of the two laps (Vavg) is twice the velocity of the 1st lap (2V1); so Vavg = 2V1 (says right in the video). Unless I'm missing something, V2 has to equal 3V1:

Since the problem states that Vavg must be 2V1, we can substitute that in the average calculation below:

So, Vavg = (V1+V2)/2 becomes 2V1 = (V1+V2)/2

Now solve for V2:

V2 = 4V1-V1
of
V2 = 3V1

i.e. your 2nd lap must always be 3x faster than your 1st lap so that the average of the two laps is twice the velocity of the 1st lap.

No?

For example:

V1 = 1 m/s
V2 = 3 m/s
Vavg = 2 m/s

2m/s = 2V1

V1 = 5m/s
V2 = 15m/s
Vavg = 10m/s or 2V1.

4 Revolutionary Riddles

Digitalfiend says...

The track question seems really straightforward, so I must be missing something.

The question is how fast do you have to run the 2nd lap such that the average of the two laps (Vavg) is twice the velocity of the 1st lap (2V1); so Vavg = 2V1 (says right in the video). Unless I'm missing something, V2 has to equal 3V1:

Since the problem states that Vavg must be 2V1, we can substitute that in the average calculation below:

So, Vavg = (V1+V2)/2 becomes 2V1 = (V1+V2)/2

Now solve for V2:

V2 = 4V1-V1
of
V2 = 3V1

i.e. your 2nd lap must always be 3x faster than your 1st lap so that the average of the two laps is twice the velocity of the 1st lap.

No?

ChaosEngine said:

Are you sure about that? Let's say the track is 100m for simplicity's sake and you run it at 1m/s (so 100s).

...

4 Revolutionary Riddles

Jinx says...

1) Some sort of viscous liquid, like honey.
2) Yeah... I thought v1=1 and v2=3, but then I realised that was actually more like t1=3, t2=1 which is not quite what the question asked.
3) Most of the bike will go forwards.
4) First thought was the wheels, but it would only ever be the very outside edge of the wheel in contact with the ground, only on driven wheels, and only if the wheel was slipping.

edit. I knew there was a reason it had to be a train and not a car. The rims of the train wheels extend past the contact point with the rails, so they will be moving backwards (well, part of them) even if the wheels don't slip.

NHL Evgeny Svechnikov - Future Trivia Answer

Fairbs says...

I tried to track down a Wings game summary video last night after getting home from a different hockey game; too many barley pops to seal the deal so thanks Milkman Dan for posting this and thanks for detailing the significance; I'd just heard young Russian scores shootout gamewinner and had visions of Datsyuk v2.0 even though that it will likely not work out as well for Evgeny; a boy can dream though...

SSL Now Enforced Site-Wide (Sift Talk Post)

ant says...

Ah. Late last night after 11 PM PST, VS was showing:

"Secure Connection Failed

An error occurred during a connection to videosift.com.

Cannot communicate securely with peer: no common encryption algorithm(s).

Error code: <a rel="nofollow" id="errorCode" title="SSL_ERROR_NO_CYPHER_OVERLAP">SSL_ERROR_NO_CYPHER_OVERLAP

The page you are trying to view cannot be shown because the authenticity of the received data could not be verified.

Please contact the website owners to inform them of this problem."


https://s28.postimg.org/9id7f2tjx/ssl.jpg for a screen shot/capture from SM's Page Info's Security tab.


I could reproduce this error in both of my computers (64-bit W7 HPE SP1 OS & 64-bit Linux/Debian Jessie/stable)'s SeaMonkey v2.46 web browsers. Also, Firefox v51 in my Debian box. I could not reproduce it in W7's IE11 & Debian's Chrome v50 web browsers that aren't based on Mozilla's Gecko engine.


I told Dag and Lucky760 about it, and it was fixed about 1.5 hours later. Kudos to the quick fixes!

radx said:

At that moment, Firefox 51.0. But I've had some ciphers disabled since the early days of Logjam attacks, which included all ciphers using Diffie-Hellman without elliptic curves. That's why there was no overlap between accepted ciphers on my end and ciphers supplied by VS.

World's Biggest Bonfire 2010

Payback says...

I figure the Parrot.ar was basically the start of ubiquitous drones. They only launched in 2010, and v2, the most popular in 2012.

Anyone with a drone in 2010 paid thousands or spent a ton of hours building one. Probably would never have gone anywhere near it.

CrushBug said:

Here is where I would have liked to have seen some crazy-close drone footage.

It's Not Easy Being Green [especially if you're The US Navy]

Mordhaus (Member Profile)

Last Week Tonight: Brexit Update

Last Week Tonight: Brexit Update

Last Week Tonight: Brexit Update

Mordhaus (Member Profile)

John Oliver - Brexit

John Oliver - Brexit

Mitchell and Webb - Jetpacks are on Sale!



Send this Article to a Friend



Separate multiple emails with a comma (,); limit 5 recipients






Your email has been sent successfully!

Manage this Video in Your Playlists

Beggar's Canyon