here's one for ya

[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...

[acolyte_to_jippity]

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

mechanical engineering.

assume that it's on the second floor, so about 10 feet, approximate to 3 meters.

now, we know the distance (roughly) the oil would drop, therefore we can calculate the kinetic energy it will have at contact with ground. factoring that into the known specific heat of oil, and extrapolating that value for a single gram (not kilogram) you can figure out exactly how much of a heat gain the oil experienced. now, since this will be a very small number, and since it is a logical assumption that:
A) the delivery man is taller than 0 cm in height
and
B) the oil drop was less than 1 gram
you can infer that the heat gain you calculated is too high, and since it will be very very low anyway, the oil would not gain enough heat to cause harm.

[brett friggin favre]

mechanical engineering.

assume that it's on the second floor, so about 10 feet, approximate to 3 meters.

now, we know the distance (roughly) the oil would drop, therefore we can calculate the kinetic energy it will have at contact with ground. factoring that into the known specific heat of oil, and extrapolating that value for a single gram (not kilogram) you can figure out exactly how much of a heat gain the oil experienced. now, since this will be a very small number, and since it is a logical assumption that:
A) the delivery man is taller than 0 cm in height
and
B) the oil drop was less than 1 gram
you can infer that the heat gain you calculated is too high, and since it will be very very low anyway, the oil would not gain enough heat to cause harm.

it wouldnt reach the velocity of 200 kph in a 2 story drop, and that uses no equations. yes it's logical, but my complaint is that he wanted us to use equations with numbers to prove it mathematically.

[Nemesis]

No it would not burn him. If he's eating a salad you have to mix the olive oil with vinegar for the dressing. if you heat vinegar you destroy the yeast in it and you cant eat it.

Unless the man eating salad was black. if he was then yes, it would be all his fault.

[christopher]

olive oil is not a great liquid phase heat transfer fluid. it has a high specific heat index greater than other normal and approximately equivalent molecular compounds.


it also has a very high viscosity ratio (compared to water and other oils), thus it is a greatly inefficient transfer fluid.


it's film coefficient is pretty low.



what does this mean? you'd need a lot of oil and a lot of time to transfer 50% of the heat of the oil to the scalp.



i'd use the film coefficient formula to explain how it'd be impossible to burn from just one drop.