First you want to find the surface area of one box
SA=2(l*w)+2(h*l)+2(h*w)
SA=2(12*12)+2(15*12)+2(15*12)
SA=2(144)+2(180)+2(180)
SA=288+360+360
SA=1008 cm² is for one box
Multiply by 4 to get for 4 boxes
4*1008=4032 cm²

4 0

3 years ago

What is the current density of the solution a/m2

Jlenok [28]

Current density of solution a/m2 is given below

Step-by-step explanation:

Current density is the measure of current generated per unit surface area of electrode.

Eg: In microbial fuel cell/fuel cells, if you are using electrode with size of 5cm x 2cm and current produced is 200mA, then current density will be,

CD= Current/(projected area of electrode)

area of rectangle= LxB= 5cm x 2cm =10cm2

CD= 200mA/10cm2

CD= 20mA/cm2

Your Current will be 200mA.

Current density will be 20mA/cm2.

8 0

3 years ago

Which expression is equivalent to sqrt8x^7y^8? assume x>0

Ilia_Sergeevich [38]

Answer:

$\sqrt{8x^7y^8$ $= 2x^3y^4 * \sqrt{2x}$

Step-by-step explanation:

Given

$\sqrt{8x^7y^8$

Required

Evaluate

$\sqrt{8x^7y^8$

Separate each factor with multiplication sign

$\sqrt{8*x^7*y^8$

Express 8 as 4 * 2 and $x^7$ as $x^6 * x$

$\sqrt{4 * 2 *x^6 * x*y^8$

Split each factor

$\sqrt{4} * \sqrt{2} *\sqrt{x^6} * \sqrt{x}*\sqrt{y^8}$

Evaluate $\sqrt4$

$2 * \sqrt{2} *\sqrt{x^6} * \sqrt{x}*\sqrt{y^8}$

Apply law of indices:

$2 * \sqrt{2} * x^{6*\frac{1}{2}} * \sqrt{x} * y^{8*\frac{1}{2}}$

$2 * \sqrt{2} * x^3 * \sqrt{x} * y^4$

Reorder

$2* x^3 * y^4 * \sqrt{2} * \sqrt{x}$

$2x^3y^4 * \sqrt{2} * \sqrt{x}$

$2x^3y^4 * \sqrt{2*x}$

$2x^3y^4 * \sqrt{2x}$

$2x^3y^4 \sqrt {2x$

Hence:

$\sqrt{8x^7y^8$ $= 2x^3y^4 * \sqrt{2x}$

8 0

3 years ago

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