Science geek brain teasers
-
The classic that is far too easy to google for now. If you have an aircraft on a conveyor belt. The air craft attempts to take off and the conveyor belt runs in the opposite direction matching the speed of the air craft. Does the plane take off?
-
I was thinking that there's enough geeks here - maths, computing, physics, you name it - that we could easily put together a bunch of questions that are answerable by most, but a little tricky. I'll start the ball rolling: Q. In a constant graviational field, how can you accelerate while keeping a steady speed? Hmm - just found braingle.com[^]. There goes a productive day...
cheers, Chris Maunder The Code Project | Co-founder Microsoft C++ MVP
Travel in a circle. Speed is distance per unit time (e.g. miles per hour). Acceleration is a change in speed OR direction. Traveling in a circle requires a constant change in direction hence a constant acceleration. I used the short explanation so as not to become too boring.
-
Yes always switch... probability of winning has just doubled after what host has done... :cool:
-
And the even more classic Monty Hall problem: Suppose you're on a game show, and you're given the choice of three doors: Behind one door is a car; behind the others, goats. You pick a door, say No. 1, and the host, who knows what's behind the doors, opens another door, say No. 3, which has a goat. He then says to you, "Do you want to pick door No. 2?" Is it to your advantage to switch your choice?
-
I was thinking that there's enough geeks here - maths, computing, physics, you name it - that we could easily put together a bunch of questions that are answerable by most, but a little tricky. I'll start the ball rolling: Q. In a constant graviational field, how can you accelerate while keeping a steady speed? Hmm - just found braingle.com[^]. There goes a productive day...
cheers, Chris Maunder The Code Project | Co-founder Microsoft C++ MVP
Ok, this is a fun one. Just jump in your car on a Sunday morning, find a big empty parking lot, crank the wheel just enough so that you can complete a circuit without crashing into anything, and set your cruise control to 5MPH. This will keep you in a constant gravitational field (near the surface of the Earth), a steady speed (courtesy of your cruise control), and under constant acceleration because you will be constantly changing direction (acceleration is defined as a change in speed or direction).
-
Bah, too easy... This site is full of geeks... Everyone should know this already... Circular orbit = Constantly accelerating toward the center of the circle, causing speed to remain constant (Only direction changes). Now, if you said constant VELOCITY, then there would be no answer :)
Proud to have finally moved to the A-Ark. Which one are you in?
Author of the Guardians Saga (Sci-Fi/Fantasy novels)Not quite right. You could have reached terminal velocity (eg. sky-diving), and so your velocity would be constant (no change in speed or direction). Unless you don't count that as a constant gravitational field because you're getting closer to earth, and therefore it's getting stronger ;P
-
Not quite right. You could have reached terminal velocity (eg. sky-diving), and so your velocity would be constant (no change in speed or direction). Unless you don't count that as a constant gravitational field because you're getting closer to earth, and therefore it's getting stronger ;P
If your velocity isn't changing, then you aren't accelerating. You're being acted upon by quite a few forces, but the net change to your velocity is still zero, and acceleration is defined as a change in velocity over time.
Proud to have finally moved to the A-Ark. Which one are you in?
Author of the Guardians Saga (Sci-Fi/Fantasy novels) -
Wrong. The engines are moving it forward but the belt is moving it backwards at the same speed. As a result its net velocity is zero meaning the wings aren't generating lift so it stays put. The only way it could get aloft is if it's a helicopter/vtol/or it's a windy day and the AC is an ultralight with a takeoff velocity lower than the wind speed. Edit: ooops.
3x12=36 2x12=24 1x12=12 0x12=18
modified on Tuesday, May 4, 2010 3:53 PM
Dan Neely wrote:
Wrong. The engines are moving it forward but the belt is moving it backwards at the same speed. As a result its net velocity is zero meaning the wings aren't generating lift so it stays put. The only way it could get aloft is if it's a helicopter/vtol/or it's a windy day and the AC is an ultralight with a takeoff velocity lower than the wind speed. Edit: ooops.
Either I'm missing a very important point, or I'm right and so WERE you... but I fully agree with everything you crossed out. Just answer one question, may I assume, that, the conveyor belt matches the planes speed so accurately that friction etc etc is ruled out and thus the resulting airspeed is 0? If so, the plane will never "take-off" since there is no lift. Edit: O.k I understand now that my assumption is invalid. The plane will eventually reach take-off velocity since the conveyor belt doesn't influence the movement generated by the jet engine/prop. But those wheels should be greased like non-other!
modified on Thursday, May 6, 2010 4:05 AM
-
Knowing that the distance from Earth to the center of the galaxy is approximately 2.5704*E17 km, is it possible to travel to the center of the galaxy during a lifetime at the speed of light? If it is, how long would it take?
If you travel at the speed of light, time is irrelevant. From the traveller's perspective, no time elapses. Therefore, there is no meaning to 'during a lifetime' for the traveller as all distances take no time at all. However, from an external observer's perspective, you could only travel for ~70 light years during a lifetime, assuming that 70 years is a typical lifespan and that the observer started observing as soon as he / she was born, as after that the observer's lifetime would have ended. (But the traveller's lifetime would not. )
-
Q. How many roads must a man walk down? :-D
Do I know what "rhetorical" means? ;P http://grammar.about.com/od/rhetoricstyle/a/homerhet.htm[^]
"These people looked deep within my soul and assigned me a number based on the order in which I joined." - Homer
-
If you travel at the speed of light, time is irrelevant. From the traveller's perspective, no time elapses. Therefore, there is no meaning to 'during a lifetime' for the traveller as all distances take no time at all. However, from an external observer's perspective, you could only travel for ~70 light years during a lifetime, assuming that 70 years is a typical lifespan and that the observer started observing as soon as he / she was born, as after that the observer's lifetime would have ended. (But the traveller's lifetime would not. )
That's correct, the meaningless of 'during lifetime' was exactly the decoy applied on a college exam some years ago. Just to add, by traveling on the speed of light, the traveler can get anywhere instantly.
-
If your velocity isn't changing, then you aren't accelerating. You're being acted upon by quite a few forces, but the net change to your velocity is still zero, and acceleration is defined as a change in velocity over time.
Proud to have finally moved to the A-Ark. Which one are you in?
Author of the Guardians Saga (Sci-Fi/Fantasy novels) -
Here's one that I don't personally have an answer to, but which has had me wondering for years. Why is the speed of light limited to 186,000 miles/second. Why this particular speed - what is the determining factor, and why can't the speed of light be exceeded?
With knowledge comes responsibilty; just think of splitting the atom as an obvious example.
The 'speed' (should be 'velocity') of light is determined by the medium that it shines through. Some esoteric materials have been created [citation needed] where light speed through them is less than walking pace. The maximum velocity of light is when it travels in a vacuum and is approx. 186282 miles per second. Any massless entity can reach this velocity (we just use 'light' as it the most well known example). Anything with mass is a victim of Einstein's famous formula: E = m c2 which, amongst a great number of other things, implies that the amount of energy required to move anything with mass grows asymptotically and to reach the velocity of light takes an infinite amount of energy. 186282 miles per second is just the theoretical limit of the velocity of an item with infinite energy. I don't know why massless entities have an upper limit as putting m = 0 into the equation comes out with E = 0. Most Sci-Fi FTL (faster than light) engines rely on warping space so that the craft still technically travel at less than light speed (sic) but the universe is distorted. The Big Bang theory uses this idea to explain how the universe expanded faster than light during an early phase called 'inflation'. Another postulated way of travelling faster than light is to jump the gap between the curve going up to infinity and its mirror on the faster than light side going down. A similar 'jumping the gap' happens at the other end of the scale in quantum physics. One interesting phenomenon of this conjecture is that you still cannot travel at light velocity itself, any more than you can rest at a complete stop.
-
The answer, my friend, is blowin' in the wind ... Bob Dylan / Peter, Paul & Mary
Steve _________________ I C(++) therefore I am
That was my answer too!
-
I was thinking that there's enough geeks here - maths, computing, physics, you name it - that we could easily put together a bunch of questions that are answerable by most, but a little tricky. I'll start the ball rolling: Q. In a constant graviational field, how can you accelerate while keeping a steady speed? Hmm - just found braingle.com[^]. There goes a productive day...
cheers, Chris Maunder The Code Project | Co-founder Microsoft C++ MVP
What is the ratio of matter to anti-matter to achieve maximum warp to get your spaceship out of the galaxy?
-
Good! The answer I learned was slightly different: As much wood as a woodchuck could chuck, if he could chuck wood.
361.9237001 cubic cm a day. http://www.wolframalpha.com/input/?i=how+much+wood+could+a+woodchuck+chuck%3F[^] :laugh: Love the annals of improbable research...
-
They aren't science geek questions, but are probably close enough ;) Q. Assuming a system which uses physical addressing mode (no virtual address space of any sort) and operates in Virtual 8086 mode, what would be the result of writing to a null pointer? Q. Where in physical memory can the RSDP be located?
OSDev :)
I'm... lost for words.
-
That's correct, the meaningless of 'during lifetime' was exactly the decoy applied on a college exam some years ago. Just to add, by traveling on the speed of light, the traveler can get anywhere instantly.
Hey, can you explain that? Sounds interesting.
-
Hey, can you explain that? Sounds interesting.
I find it really difficult to explain to my brothers without actually using physics theories and equations. But the basic concept is that the faster you travel, the slower the time passes to you (for everyone else watching you travel, time passes in their own pace). A very know example is the "Twins Paradox" and astrounauts. Because astronauts travel at high speeds in orbit, they age slower (we can't notice because the amount is very small amount). This video[^] explains it a little better. There are equations that allows you to calculate the amount of time that passes depending on speed, but I won't go that deep here. I hope that makes a little better for you to understand. Regards, Fábio
