here's one for ya

[brett friggin favre]

just took a test, and we had to solve this:

a guy's eating a salad on his balcony and unknowingly drips a drop of olive oil onto a pizza delivery man below, who sues for $10m because he claims the olive oil burned his scalp. prove that this is not possible

we were told to ignore heat loss to the air while falling, heat gain due to friction, and were not given a starting temperature or the temperature needed to burn the human scalp. we were given the specific heat of the oil as 1.97 kj/kg*°K.

this is an introduction to mechanical engineering course. i repeat, INTRODUCTION. the prof used to teach thermodynamics at MIT. now if i was in thermodynamics at MIT i bet i could figure this out, but for an INTRO TO FUCKING MECHANICAL ENGINEERING COURSE i think this is a bit absurd.

[Penis シ]

A few things. 1. Why does he have hot olive oil on a salad? That's gross. 2. Why is he ordering pizza if he has a salad? That's just gluttonous. 3. Why is he eating salad OVER his balcony? That's just stupid. 4. Even if he is dumb enough, why is the bowl far out enough that he can drip on the way to his mouth while leaning out? That's just silly.

Please speak with your asshole professor and answer these for me.

[brett friggin favre]

A few things. 1. Why does he have hot olive oil on a salad? That's gross. 2. Why is he ordering pizza if he has a salad? That's just gluttonous. 3. Why is he eating salad OVER his balcony? That's just stupid. 4. Even if he is dumb enough, why is the bowl far out enough that he can drip on the way to his mouth while leaning out? That's just silly.

Please speak with your asshole professor and answer these for me.

i wrote him a little note saying "i have no idea what you want. you want me to prove that, ignoring many heating factors, olive oil could not rise from an unknown temperature to another unknown temperature. so i'm gonna say no, the sun can't heat up olive oil however much that is. and why the hell does it matter that it reaches 200 km/h while it falls if we're supposed to ignore frictional heating with the air? why the hell does it matter whether or not it splattered when it hit his hat because i wouldn't know what it splattering would even mean because you never even discussed any of this with us, and neither did the book."

[SCRIBBLE]

just took a test, and we had to solve this:

a guy's eating a salad on his balcony and unknowingly drips a drop of olive oil onto a pizza delivery man below, who sues for $10m because he claims the olive oil burned his scalp. prove that this is not possible

we were told to ignore heat loss to the air while falling, heat gain due to friction, and were not given a starting temperature or the temperature needed to burn the human scalp. we were given the specific heat of the oil as 1.97 kj/kg*°K.

this is an introduction to mechanical engineering course. i repeat, INTRODUCTION. the prof used to teach thermodynamics at MIT. now if i was in thermodynamics at MIT i bet i could figure this out, but for an INTRO TO FUCKING MECHANICAL ENGINEERING COURSE i think this is a bit absurd.

first thing i would note is that it would technically be a scald as opposed to a burn. also to prove the oil was not hot enough to burn his scalp all you have to do is remember hot oil and water does not mix -- therefore if the oil was on the salad (vegetables made up primarily of water) and was hot enough to burn someone it would have reacted violently with the water in the salad. hot oil has a higher temperature than that of steam so when the hot oil hits the water, steam is created and expands violently. so the proof lies in the fact that the salad wasn't wilted and steam wasn't shooting out of the bowl.

hot oil is also less viscous than oil at room temperature and would probably separate to the point of a spray due to turbulence created by the air while falling if the oil was hot.

intro to thermodynamics man... that was an easy question though an MIT professor should have known the difference between a scald and a burn.

A few things. 1. Why does he have hot olive oil on a salad? That's gross. 2. Why is he ordering pizza if he has a salad? That's just gluttonous. 3. Why is he eating salad OVER his balcony? That's just stupid. 4. Even if he is dumb enough, why is the bowl far out enough that he can drip on the way to his mouth while leaning out? That's just silly.

Please speak with your asshole professor and answer these for me.

1. subjective
2. not stated that he ordered a pizza at all
3. it was stated he was eating it on the balcony, not over
4. again, subjective, all people do not eat the same

[brett friggin favre]

it's not an intro to thermodynamics though. we use different course terminology here but it's essentially ME 101.

[Andrew_Pavlik]

Did you ever find out the answer? It seems more of a riddle then an ME question. Even if you could add the heat due to friction, just plain olive oil couldn't heat up enough from friction to burn someone, well not from the height that it would drop. Also he never gave you the height of the eater there for obviously it had nothing to do with how far it travels.

I mean olive oil can burn, well be used for lamps and such, but you'd have to get it pretty hot. So I guess it's pretty easy to prove it's not possible, oils burn around something like ~350'C so you could say that in order for the oil to burn, it would have been at temps much higher then to cause a burn also it would have been on fire unlike a boiling drop of water.

[brett friggin favre]

Did you ever find out the answer? It seems more of a riddle then an ME question. Even if you could add the heat due to friction, just plain olive oil couldn't heat up enough from friction to burn someone, well not from the height that it would drop. Also he never gave you the height of the eater there for obviously it had nothing to do with how far it travels.

I mean olive oil can burn, well be used for lamps and such, but you'd have to get it pretty hot. So I guess it's pretty easy to prove it's not possible, oils burn around something like ~350'C so you could say that in order for the oil to burn, it would have been at temps much higher then to cause a burn also it would have been on fire unlike a boiling drop of water.

nope, never found the answer. all i can think is maybe he wanted us to assume it started super hot, so hot that it would be impossible and as you said, would combust. but that part was unclear and unless told otherwise, i'm gonna assume this guy didn't get his olive oil from his personal star microwave so it'd be hot enough for it to happen. i'm gonna assume it started at room temp because that's what people do. it's practical. it's engineering. and EVEN IF we assume it started super hot and somehow didn't combust or turn to vapor, and that it'd be cooling down as it decended, we're still not given how hot it had to be to burn the guy or how long it fell. he tells us it falls long enough to reach its terminal velocity of 200 kph, but doesn't say how long it fell at that speed or how high the balcony was. we also don't have the mass of the droplet, nor the surface area.

[Penis シ]

A little googling. Turns out that's pretty cold.
http://www.engineeringtoolbox.com/wa...ies-d_162.html

Granted that's with water and not oil.

[SCRIBBLE]

just took a test, and we had to solve this:

a guy's eating a salad on his balcony and unknowingly drips a drop of olive oil onto a pizza delivery man below, who sues for $10m because he claims the olive oil burned his scalp. prove that this is not possible

we were told to ignore heat loss to the air while falling, heat gain due to friction, and were not given a starting temperature or the temperature needed to burn the human scalp. we were given the specific heat of the oil as 1.97 kj/kg*°K.

this is an introduction to mechanical engineering course. i repeat, INTRODUCTION. the prof used to teach thermodynamics at MIT. now if i was in thermodynamics at MIT i bet i could figure this out, but for an INTRO TO FUCKING MECHANICAL ENGINEERING COURSE i think this is a bit absurd.

Woops, I put too much thought into this one. He's eating a salad so, if the oil is so hot that it would burn a scalp, it would burn his tongue. How to prove it's not possible? Look at his tongue.

[brett friggin favre]

Woops, I put too much thought into this one. He's eating a salad so, if the oil is so hot that it would burn a scalp, it would burn his tongue. How to prove it's not possible? Look at his tongue.

that'd be the answer if it were a riddle, as mentioned above. but he wanted equations and stuff. if only...