A) To find the surface area of a cube, you have to use the formula 6•a^2
meaning you just have to calculate one side and multiply it by six.
541.5 is the surface area of the cube.
B) To find the surface area for just five sides, you'll be doing the same, except instead of 6 it'll be five.
so multiply 9.5 by itself
you get 90.25
Then you multiply 90.5 by 5
You get 451.25
Unfortunately I'm not sure how to do C. good luck
Answer:
the answer is 8/17
Step-by-step explanation:
i got it right on the quiz
Answer:
The answer is below
Step-by-step explanation:
a) The maximum capacity of he tank is 6 L and initially it contains 11 mg of salt dissolved in 3 L of water. Solution enters the tank at a rate of 3 L/hr, therefore in x hours, the amount of water that have entered the tank = 3x.
Solution also leaves the tank at a rate of 2L/hr, therefore in x hours, the amount of water that have left the tank = 2x
Hence the amount of water present in the tank at x hours is given as:
3 + 3x - 2x = 3 + x
The time taken to full the tank can be gotten from:
3 + x = 6
x = 6 - 3
x = 3 hr
b)
![\frac{dQ}{dx}=3-\frac{2Q}{3+x}\\ \\\frac{dQ}{dx}+\frac{2Q}{3+x}=3\\\\let\ u'=\frac{2u}{3+x}\\\\\frac{u'}{u}=\frac{2Q}{3+x}\\\\ln(u)=2ln(3+x)\\\\u=(3+x)^2\\\\(3+x)^2Q]'=3(3+x)^2\\\\(3+x)^2Q=(3+x)^3+c\\\\Q(0)=11\\\\(3+0)^2(11)=(3+0)^3+c\\\\x=72\\\\Q=x+3+\frac{72}{(x+3)^2}\\ \\Q(3)=3+3+\frac{72}{(3+3)^2}=8\ mg](https://tex.z-dn.net/?f=%5Cfrac%7BdQ%7D%7Bdx%7D%3D3-%5Cfrac%7B2Q%7D%7B3%2Bx%7D%5C%5C%20%20%5C%5C%5Cfrac%7BdQ%7D%7Bdx%7D%2B%5Cfrac%7B2Q%7D%7B3%2Bx%7D%3D3%5C%5C%5C%5Clet%5C%20u%27%3D%5Cfrac%7B2u%7D%7B3%2Bx%7D%5C%5C%5C%5C%5Cfrac%7Bu%27%7D%7Bu%7D%3D%5Cfrac%7B2Q%7D%7B3%2Bx%7D%5C%5C%5C%5Cln%28u%29%3D2ln%283%2Bx%29%5C%5C%5C%5Cu%3D%283%2Bx%29%5E2%5C%5C%5C%5C%283%2Bx%29%5E2Q%5D%27%3D3%283%2Bx%29%5E2%5C%5C%5C%5C%283%2Bx%29%5E2Q%3D%283%2Bx%29%5E3%2Bc%5C%5C%5C%5CQ%280%29%3D11%5C%5C%5C%5C%283%2B0%29%5E2%2811%29%3D%283%2B0%29%5E3%2Bc%5C%5C%5C%5Cx%3D72%5C%5C%5C%5CQ%3Dx%2B3%2B%5Cfrac%7B72%7D%7B%28x%2B3%29%5E2%7D%5C%5C%20%5C%5CQ%283%29%3D3%2B3%2B%5Cfrac%7B72%7D%7B%283%2B3%29%5E2%7D%3D8%5C%20mg)
8 mg/ 6 L = 4/3 mg/L