I was at an interview in DC a couple weeks ago and this question came up.
It’s a popular interview question used at Microsoft
So with out looking up the possible answer post up…
pointy shapes make me insecure
x2
My father in law used to interview engineers and would ask: You’re in a little boat in a swimming pool. There’s a big rock in the boat with you. You throw the rock overboard into the pool. Does the water level of the pool go up, down, or stay the same?
there are two reasons.
The first has already been posted.
The second is because “man-holes” ARE round.
Stays the same.
And they’re round because it’s the only shape that no matter how you turn it you can’t cause it to fall through the hole.
Plus, where would TV comedy be without the fat guy who can’t quite fit through the round opening skit? It wouldn’t be nearly as funny with a square hole because he wouldn’t fill it completely.
because manholes are round
how would you answer that?
The water level goes down. A buoyant object (like a boat/rock/person system) will displace an amount of water equal to its weight. A non-bouyant object like a rock will displace an amount of water equal to its volume. Since the rock is denser than water, an equal weight of water is more volume than the rock.
plus they are easier to manufacture/press…
hrmm this would be a good thesis paper…
I’d say it’s because there isn’t one specific point of weakness. Best load distribution.
umm… the water level would stay the same…
edit: thinking into it more… I guess the density of the rock would come into play
heheheh sweet
Can a race car lift a manhole cover?
Modern racing cars create so much vacuum due to their aerodynamics that they can lift a manhole cover off the ground. During races on city streets, the manhole covers must therefore be welded down to prevent injury. In 1990, during the Group C World Sportscar Championship race in Montreal, racer Jésus Pareja’s car struck a manhole cover that was lifted by the ground effect of the car he was following, causing his car to catch fire.[5]
i dont know if i agree with that… volume is what causes the displacement… if the object is more dense than the water it will sink and cause the water to displace its volume… i think there would be extremes at both ends, if the item in the raft (im picturing an inflatable raft) and a rock for one extreme and some composite lighter weight object (that would still sink) as the other…
meh im quitting there… i dont feel like typing…
man hole covers are round so they dont ever fall in… /thread
another good question is: “your from Buffalo I see, how many gas stations are there in Buffalo?”
HAHA! YES!
if manholes were square, their covers wouldn’t be circular.
This pissed me off because we were talking about something else…and then the people interviewing me go by the way why are man hole covers round…
pause