Random Thoughts Part 5: Time to Split Again

[Psinter]

kick the door and always ask for cigarettes and matches yelling and calling me names when I refuse.

That reminded me about the Bugs Bunny in Looney Tunes that gave trap cigarretes to the bad guys and they always went... But don't that, a lot could go wrong. I'm just hearing the Looney Tunes intro music and it's funny. Plus, today is April's Fools which make it even more funny when I think it in my mind. ♫ Uuuu para pa pa pa para pa pa pa pa. Ticu ticu ticu tin ticu ticu tin. Uuuuu para pa pa, papara pa pa pa. Tinuninu tinuninu tata tata tatan tan! ♫

Wow, it's my birthday. Snuck up on me this year. Or I was trying to block it out.

Really? Happy birthday!

April fools...

You realize when there is a new button in the YouTube videos.

 

[Sophia]

That reminded me about the Bugs Bunny in Looney Tunes that gave trap cigarretes to the bad guys and they always went... But don't that, a lot could go wrong. I'm just hearing the Looney Tunes intro music and it's funny. Plus, today is April's Fools which make it even more funny when I think it in my mind. ♫ Uuuu para pa pa pa para pa pa pa pa. Ticu ticu ticu tin ticu ticu tin. Uuuuu para pa pa, papara pa pa pa. Tinuninu tinuninu tata tata tatan tan! ♫ [emoji3]

Music of my childhood!

 

[Psinter]

Mine too!

 

[ProfuselyQuarky]

 

[WWGD]

Music of my childhood!

I thought it

They would be proud of it. In their culture it is normal to do things like that. If anyone is interested I may send the video of what am I talking about in a PM. It's part of a larger social problem.
Showing them on YouTube would work for kids from middle or upper class families.
I will record them in order to show it to the local police but posting it on yt would have no effect.

I don't mean to insist, I was thinking of focusing on what the police allows them to do, to pressure the police into taking action and not be embarrassed.

 

[WWGD]

Howard U, the friendliest university in the U.S.

 

[Borg]

MTU is the hungriest.

 

[WWGD]

MTU is the hungriest.

MTU??

 

[ProfuselyQuarky]

MTU??

Michigan Tech?

 

[WWGD]

Michigan Tech?

Yes, but why is it the hungriest. The world's hungriest is in Budapest.

 

[Borg]

Michigan Tech?

Yes.
Michigan Technological University

Yes, but why is it the hungriest. The world's hungriest is in Budapest.

Keep saying MTU until you get it.

 

[ProfuselyQuarky]

Keep saying MTU until you get it.

Aha! I got it! What about you, @WWGD?

 

[Sophia]

I thought it

I don't mean to insist, I was thinking of focusing on what the police allows them to do, to pressure the police into taking action and not be embarrassed.

Oh now i get it

 

[Sophia]

Aha! I got it! What about you, @WWGD?

Does it become "empty you" ?
Or am I totally wrong :-)

 

[ProfuselyQuarky]

Does it become "empty you" ?
Or am I totally wrong :-)

That's what I got out of it

 

[Borg]

Does it become "empty you" ?

Yes. I really didn't think that it was that hard.

 

[Astronuc]

Brave little man - Family Asks for Birthday Cards for Boy Who Survived Brain Cancer
https://gma.yahoo.com/video/family-asks-birthday-cards-boy-173123747.html

 

[WWGD]

No one took my bait for Budapest U :( . (Better as a spoken joke than as a written one)

 

[zoobyshoe]

I got a birthday present for my car, even though it's not my car's birthday: a new set of tires.

Tires for the old air-cooled VW's are hard to find nowadays. Tire outlets just don't sell them, and you have to order them online. I ordered 5 of them, and they came yesterday by UPS. For some reason I thought they would be in boxes, but they were shipped unboxed, just plastered with a bunch of stickers. All in all, probably the best way to do it considering how sturdy tires inherently are.

Anyway, I had them put on today at the local used tire garage. They charged $10.00 per tire, plus an extra $2.00 per tire to balance them. That came to $60.00 just to have them put on. I'm not sure how I feel about that. But there's pretty much no way a person can do that himself without one of those machines to get it on and off the rims.

Driving away, I found everything was so much better! The ride was much smoother, almost as if I'd replaced the shocks. The steering seems über-responsive now. The tires I had before were from 2002 and obviously past the tread wear limit. I think I will get a proper alignment and do the regularly recommended tire rotation, including the spare, from now on.

 

[WWGD]

I got a birthday present for my car, even though it's not my car's birthday: a new set of tires.

Tires for the old air-cooled VW's are hard to find nowadays. Tire outlets just don't sell them, and you have to order them online. I ordered 5 of them, and they came yesterday by UPS. For some reason I thought they would be in boxes, but they were shipped unboxed, just plastered with a bunch of stickers. All in all, probably the best way to do it considering how sturdy tires inherently are.

Anyway, I had them put on today at the local used tire garage. They charged $10.00 per tire, plus an extra $2.00 per tire to balance them. That came to $60.00 just to have them put on. I'm not sure how I feel about that. But there's pretty much no way a person can do that himself without one of those machines to get it on and off the rims.

Driving away, I found everything was so much better! The ride was much smoother, almost as if I'd replaced the shocks. The steering seems über-responsive now. The tires I had before were from 2002 and obviously past the tread wear limit. I think I will get a proper alignment and do the regularly recommended tire rotation, including the spare, from now on.

Happy Birthday, ZooVyeW !

 

[zoobyshoe]

Happy Birthday, ZooVyeW !

 

[Psinter]

Driving away, I found everything was so much better! The ride was much smoother, almost as if I'd replaced the shocks. The steering seems über-responsive now. The tires I had before were from 2002 and obviously past the tread wear limit. I think I will get a proper alignment and do the regularly recommended tire rotation, including the spare, from now on.

Yes, changing the tires makes a huge difference on how the vehicle feels.

A random fun exercise I came up with after browsing random images:

Spoiler: The Problem

If the water in the image falls down with acceleration 9.81\frac{m}{s^2}, how much does the human has to accelerate to avoid the water from touching her? Give your answer in \frac{m}{s^2}. Assume the water in the image has a distance of 1m above of the human, initial velocity is 0 for both the human and the slab of water, neglect air resistance.

Is it possible for a human in that position to accelerate at the rate of your answer and avoid being touched by the water?

It's been so long since I tried an exercise like this, but here is my answer:

Spoiler: My Answer

The water will touch her in approximately 0.45 seconds. That means she needs to move all of her body mass to the side approximately 0.61m (2ft) in less than 0.45 seconds.

The equations of motion yield that the human must at minimum accelerate all of her body at approximately 5.93 m/s^2.

I don't know if a human can do such in that position. Calculations:

The slab of water:
x = x_{0} + v_{0}t + \frac{1}{2}at^2 \\\\<br /> 1m = 0m + 0t + \frac{1}{2}(9.81\frac{m}{s^2})(t^2)\\\\<br /> <br /> \frac{(1m)(2)}{9.81\frac{m}{s^2}} = t^2 \\\\<br /> <br /> t = \pm \sqrt{\frac{2m}{9.81\frac{m}{s^2}}} \\\\<br /> <br /> t\approx \pm 0.45s

The human:
<br /> x = x_{0} + v_{0}t + \frac{1}{2}at^2 \\\\ <br /> 0.60m = 0m + 0(0.45s) + \frac{1}{2}(a)(0.45s)^2\\\\<br /> \frac{(0.60m)(2)}{(0.45s)^2} = a\\\\<br /> a = 5.93 \frac{m}{s^2}

In the end I can get the numbers, but it beats me whether a human can accelerate at that rate in such a position using its muscles.

 

[JorisL]

The fastest would be to roll to the side I think.
However 450 ms requires one to react very fast.

All in all I doubt its possible to get away dry.

 

[Psinter]

The fastest would be to roll to the side I think.
However 450 ms requires one to react very fast.

All in all I doubt its possible to get away dry.

You are right. I hadn't taken reaction time into account, but if we take it into account I guess we can safely assume that she got touched by the water. A reaction time would mean the acceleration must be bigger in order to avoid the water as her time to get away from it would become less than 450 ms.

 

[JorisL]

If I recall correctly a bachelors thesis at my first school did test the reaction speed with a light (random wavelength) and the user had to push a button to register.
I recall the average was about 300 ms for green light (most sensitive for humans).

You can add another layer and wonder at what height one could safely roll aside with a reaction time of 300 ms.

That would mean you need to guesstimate the maximal acceleration though.

 

[zoobyshoe]

I was in the checkout line at Walmart. There was a fairly loud pop behind me, and I saw some "shrapnel" skitter across the floor by my feet. Turned out a woman had dropped a bottle of red wine about ten feet back. There was quite an interesting crimson lake to be dealt with, and in a few moments the smell of it reached me. It was pretty powerful.

On my way out to the car I noticed that kind of scraping feeling on the bottom of my shoe that tells you you've picked up a pebble or something hard. I figured it must be a piece of wine bottle. I tried to scrape it off onto the tar, but it seemed to be lodged in deep.

Having arrived home (which I believe is the Latin Ablative Absolute) I checked my shoe and was surprised to find out it wasn't a piece of glass at all, but a very thick splinter of wood. It was also in quite deep. I had to use pliers to get it out. No idea where I'd picked it up.

Seems so odd life would present such a thorough and plausible explanation of why I had something in my shoe, but then it turns out to have nothing to do with what was in my shoe.

 

[Psinter]

If I recall correctly a bachelors thesis at my first school did test the reaction speed with a light (random wavelength) and the user had to push a button to register.
I recall the average was about 300 ms for green light (most sensitive for humans).

You can add another layer and wonder at what height one could safely roll aside with a reaction time of 300 ms.

That would mean you need to guesstimate the maximal acceleration though.

I see. With a visual reaction time of 300 ms, the human would have left only a little more than 100 ms to accelerate. Which means that the human would need to accelerate about 12m/s^2 to avoid the water. Now that is fast. A considerable increase in the original calculations. It's a little more than double after all.

Edit: Haha! I hovered the top banner of the page and was surprised by a certain someone. I thought I was at a fake page and panicked for a few milliseconds there.

 

[WWGD]

Kind of weird. Zoned out and I watched an infomercial for around an hour. And I did not even notice what it was about.

 

[Psinter]

Kind of weird. Zoned out and I watched an infomercial for around an hour. And I did not even notice what it was about.

I have been caught a few times zoning out. Although never when I have been thinking of a person I like. All of the times have been while thinking about technical stuff.

Do you imagine zoning out by thinking of the person you like while being in front of the person you like? That must be embarrassing.

 

[JorisL]

@Psinter You should start a thread dedicated to that kind of problem.
It could prove an invaluable resource for students and people that aren't very knowledgeable about physics.

I would see it as a motivation for demotivated students as well, the kind that asks "what's the use of all this".