question:
How many cubes with side lengths of \dfrac12 \text{ cm} 2 1 cmstart fraction, 1, divided by, 2, end fraction, start text, space, c, m, end text does it take to fill the prism?
Step-by-step explanation:
81 cubes are needed to fill the prism
Step-by-step explanation:
Volume of prism = 3 cubic units
Side lengths of cube = 1/3
Therefore the volume of the cube is,
V = a³ (a = side of the cube)
V = 1/3 × 1/3 × 1/3
= ( 1/3 )³
= 1/27 cubic units
To find the number of cubes needed to fill the prism, we need to divide the volume of cube by volume of the prism.
Number of cubes to fill the prism= Volume of prism / Volume of cube
= 3÷1/27
=3×27/1
= 81
Therefore, 81 cubes are needed to fill the prism
Answer:
![A=1500-1450e^{-\dfrac{t}{250}}](https://tex.z-dn.net/?f=A%3D1500-1450e%5E%7B-%5Cdfrac%7Bt%7D%7B250%7D%7D)
Step-by-step explanation:
The large mixing tank initially holds 500 gallons of water in which 50 pounds of salt have been dissolved.
Volume = 500 gallons
Initial Amount of Salt, A(0)=50 pounds
Brine solution with concentration of 2 lb/gal is pumped into the tank at a rate of 3 gal/min
=(concentration of salt in inflow)(input rate of brine)
![=(2\frac{lbs}{gal})( 3\frac{gal}{min})\\R_{in}=6\frac{lbs}{min}](https://tex.z-dn.net/?f=%3D%282%5Cfrac%7Blbs%7D%7Bgal%7D%29%28%203%5Cfrac%7Bgal%7D%7Bmin%7D%29%5C%5CR_%7Bin%7D%3D6%5Cfrac%7Blbs%7D%7Bmin%7D)
When the solution is well stirred, it is then pumped out at a slower rate of 2 gal/min.
Concentration c(t) of the salt in the tank at time t
Concentration, ![C(t)=\dfrac{Amount}{Volume}=\dfrac{A(t)}{500}](https://tex.z-dn.net/?f=C%28t%29%3D%5Cdfrac%7BAmount%7D%7BVolume%7D%3D%5Cdfrac%7BA%28t%29%7D%7B500%7D)
=(concentration of salt in outflow)(output rate of brine)
![=(\frac{A(t)}{500})( 2\frac{gal}{min})\\R_{out}=\dfrac{A}{250}](https://tex.z-dn.net/?f=%3D%28%5Cfrac%7BA%28t%29%7D%7B500%7D%29%28%202%5Cfrac%7Bgal%7D%7Bmin%7D%29%5C%5CR_%7Bout%7D%3D%5Cdfrac%7BA%7D%7B250%7D)
Now, the rate of change of the amount of salt in the tank
![\dfrac{dA}{dt}=R_{in}-R_{out}](https://tex.z-dn.net/?f=%5Cdfrac%7BdA%7D%7Bdt%7D%3DR_%7Bin%7D-R_%7Bout%7D)
![\dfrac{dA}{dt}=6-\dfrac{A}{250}](https://tex.z-dn.net/?f=%5Cdfrac%7BdA%7D%7Bdt%7D%3D6-%5Cdfrac%7BA%7D%7B250%7D)
We solve the resulting differential equation by separation of variables.
![\dfrac{dA}{dt}+\dfrac{A}{250}=6\\$The integrating factor: e^{\int \frac{1}{250}dt} =e^{\frac{t}{250}}\\$Multiplying by the integrating factor all through\\\dfrac{dA}{dt}e^{\frac{t}{250}}+\dfrac{A}{250}e^{\frac{t}{250}}=6e^{\frac{t}{250}}\\(Ae^{\frac{t}{250}})'=6e^{\frac{t}{250}}](https://tex.z-dn.net/?f=%5Cdfrac%7BdA%7D%7Bdt%7D%2B%5Cdfrac%7BA%7D%7B250%7D%3D6%5C%5C%24The%20integrating%20factor%3A%20e%5E%7B%5Cint%20%5Cfrac%7B1%7D%7B250%7Ddt%7D%20%3De%5E%7B%5Cfrac%7Bt%7D%7B250%7D%7D%5C%5C%24Multiplying%20by%20the%20integrating%20factor%20all%20through%5C%5C%5Cdfrac%7BdA%7D%7Bdt%7De%5E%7B%5Cfrac%7Bt%7D%7B250%7D%7D%2B%5Cdfrac%7BA%7D%7B250%7De%5E%7B%5Cfrac%7Bt%7D%7B250%7D%7D%3D6e%5E%7B%5Cfrac%7Bt%7D%7B250%7D%7D%5C%5C%28Ae%5E%7B%5Cfrac%7Bt%7D%7B250%7D%7D%29%27%3D6e%5E%7B%5Cfrac%7Bt%7D%7B250%7D%7D)
Taking the integral of both sides
![\int(Ae^{\frac{t}{250}})'=\int 6e^{\frac{t}{250}} dt\\Ae^{\frac{t}{250}}=6*250e^{\frac{t}{250}}+C, $(C a constant of integration)\\Ae^{\frac{t}{250}}=1500e^{\frac{t}{250}}+C\\$Divide all through by e^{\frac{t}{250}}\\A(t)=1500+Ce^{-\frac{t}{250}}](https://tex.z-dn.net/?f=%5Cint%28Ae%5E%7B%5Cfrac%7Bt%7D%7B250%7D%7D%29%27%3D%5Cint%206e%5E%7B%5Cfrac%7Bt%7D%7B250%7D%7D%20dt%5C%5CAe%5E%7B%5Cfrac%7Bt%7D%7B250%7D%7D%3D6%2A250e%5E%7B%5Cfrac%7Bt%7D%7B250%7D%7D%2BC%2C%20%24%28C%20a%20constant%20of%20integration%29%5C%5CAe%5E%7B%5Cfrac%7Bt%7D%7B250%7D%7D%3D1500e%5E%7B%5Cfrac%7Bt%7D%7B250%7D%7D%2BC%5C%5C%24Divide%20all%20through%20by%20e%5E%7B%5Cfrac%7Bt%7D%7B250%7D%7D%5C%5CA%28t%29%3D1500%2BCe%5E%7B-%5Cfrac%7Bt%7D%7B250%7D%7D)
Recall that when t=0, A(t)=50 (our initial condition)
![50=1500+Ce^{-\frac{0}{250}}50=1500+Ce^{0}\\C=-1450\\$Therefore the amount of salt in the tank at any time t is:\\A=1500-1450e^{-\dfrac{t}{250}}](https://tex.z-dn.net/?f=50%3D1500%2BCe%5E%7B-%5Cfrac%7B0%7D%7B250%7D%7D50%3D1500%2BCe%5E%7B0%7D%5C%5CC%3D-1450%5C%5C%24Therefore%20the%20amount%20of%20salt%20in%20the%20tank%20at%20any%20time%20t%20is%3A%5C%5CA%3D1500-1450e%5E%7B-%5Cdfrac%7Bt%7D%7B250%7D%7D)
Answer:
0.058
Step-by-step explanation:
Answer:
Step-by-step explanation:
7 friends plus himself = 8 persons
Round trip flight cost = &389x8= & 3112
Hotel bill = &249 x 4 rooms 3 nights = &
& 2988
Cost at Observatory desk = & 18.5 x 8= & 148
Cost at base ball viewing venue = 38 x 8 = & 148
Total budget apart from feeding should be = & 6552
Answer:
2r+12c
Step-by-step explanation: