OT: Calculus Challenge of the day.

[liquidtiger720]

So, here's today's Assignment for you guys to solve.


There is a very strong radiation source in the center of a large 120 x 120 foot room. A person must run through this room to get to safety. Her escape route takes her the full lenth along one wall of the room. She is not exposed to radiation outside the room. The strength of the radiation is inversely proprtional to the square of her distance from the source. At 5- feet, her body is absorbing radiation at the rate of 200 un**** per second. If she runs at 12 feet per second, what is the tottal radiation dose she recieves during her dash to safety?


You must show the integral used to solve problem.

[Blitzkrieg Bob]

and heat a cup of green tea

[liquidtiger720]

haha...cmon, where are the mechanical/civil engineers on the board?

[DaveVoorhis]

Oy! Yer just trying to get someone to do your homework assignment for you, aren't you?

[liquidtiger720]

Not DO it...just HELP. hahaha.

[rob101]

Yes there are mech engineers on the board, but speaking for myself i finished university so that i would never have to do stuff like that again......... but I'll see what i can come up with

[rob101]

okay dokey
R = rate of rad absorption (units/sec)
x = distance from the source (feet)
k = constant

now R = k/(x^2)
so 200 units/s = k/(5^2)
therefore k = 5000

now in order to solve this you need to find the total units of rad she absorbed

so that will be the Integral of R with respect to time

you will need to find an expression for the distance with respect to time.
that is to say x= f(t)
probably some kind of parabola
then you will find the Integral of k/(x^2) with respect to time
ie integral of 5000/(f(t)^2) with respect to time

you bastard, the horrible memories are flowing back...... nooooooo

edit: the expression for x is something like x = sqrt((60-ut)^2+60^2)
where sqrt is the square root and u is the chick's velocity

[Bellicose Right Winger]

10.9 units

So, here's today's Assignment for you guys to solve.


There is a very strong radiation source in the center of a large 120 x 120 foot room. A person must run through this room to get to safety. Her escape route takes her the full lenth along one wall of the room. She is not exposed to radiation outside the room. The strength of the radiation is inversely proprtional to the square of her distance from the source. At 5- feet, her body is absorbing radiation at the rate of 200 un**** per second. If she runs at 12 feet per second, what is the tottal radiation dose she recieves during her dash to safety?


You must show the integral used to solve problem.

[liquidtiger720]

i just noticed a type while going through the proble....5- is suppose ot be 50. But I think I can manage. Thank you everybody for the well needed boost. Rob and Bellicose, you deserve a cookie!.


sorry to bring back bad memories rob!

[632 Regal]

integral is "*&*^%%^$(]}@{" - without the ""s
the answer is 6