--&& Daily Math/Physics Questions Thread &&--

[TheAnointedOne]

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[R.E.N. Spells Ren]

Softball one

Difficulty: Easy
Category: Calculus

lim {x -> 1} ( x^2 + x - 1 ) / ( x - 1 )

Note: It reads 'limit as x approaches one'.
'^' this symbol signifies exponent. So 'x^2' reads 'x to the 2nd power'.
'/' signifies division. So '3 / 2' reads '3 divided by 2'

♾

far too easy

Topic is a flop. Folks would rather talk about celebrity gossip.

Well you are posting this in The Locker Room on the Coli, why would you expect anything different.

 

[TheAnointedOne]

Difficulty: Medium
Category: Physics

In the fall of 2002, scientists at Los Alamos National Laboratory determined that the critical mass of neptunium-237 is about 60 kg. The critical mass of a fissionable material is the minimum amount that must be brought together to start a nuclear chain reaction. Neptunium-237 has a density of 19.5 g/cm^3. What would be the radius of a sphere of this material that has a critical mass?

 

[TheAnointedOne]

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[R.E.N. Spells Ren]

Way more activity here.

Yes and that activity is centered around celebrity gossip, so why act surprised or offended. It is what it is.

 

[DrBanneker]

Difficulty: Medium
Category: Physics

In the fall of 2002, scientists at Los Alamos National Laboratory determined that the critical mass of neptunium-237 is about 60 kg. The critical mass of a fissionable material is the minimum amount that must be brought together to start a nuclear chain reaction. Neptunium-237 has a density of 19.5 g/cm^3. What would be the radius of a sphere of this material that has a critical mass?

Mass = Density x Volume

60,000 g = 19.5 g /cm^3 x 4/3 x pi x r^3

r = 9 cm

 

[TheAnointedOne]

Mass = Density x Volume

60,000 g = 19.5 g /cm^3 x 4/3 x pi x r^3

r = 9 cm

You are correct.

My notes

density = mass / volume
critical mass = 60 kg
density = 19.5 g/cm^3

volume = mass / density
volume = 60000 g / 19.5 g/cm^3
volume = 3,076.9 cm^3
4/3*pi*r^3 = 3,076.9 cm^3
r^3 = 3,076.9 cm^3 / 4/3*pi
r^3 = 3,076.9 cm^3 / 4.1888
r^3 = 734.3
r = sqrt^3(734.3)
r = 9.0217
r = 9.0 cm

 

[TheAnointedOne]

Different type of question

Difficulty: Easy
Category: Math/Brain Teaser

 

[MarcMan]

Different type of question

Difficulty: Easy
Category: Math/Brain Teaser

Spoiler

-6

 

[8.TRES]

Spoiler

-6

facts

 

[T.H.E. Goat]

Different type of question

Difficulty: Easy
Category: Math/Brain Teaser

This more my speed



Answer is -6




Edit: Too late

 

[8.TRES]

This more my speed



Answer is 6



Monkeys = 6
Bird = 4
Bee = 3

pemdas

 

[TheAnointedOne]

Spoiler

-6

This more my speed



Answer is -6




Edit: Too late

Unfortunately you're both wrong.

 

[MarcMan]

Unfortunately you're both wrong.

Oh right, three monkeys then one, whatever.

Spoiler

-10

 

[T.H.E. Goat]

Unfortunately you're both wrong.

Spoiler: spoiler

multiplication before subtraction?

4 x 3 - 6 = 6