Answer:
Could you explain it another way?
Step-by-step explanation:
Width = X
Length = X + 15
Perimeter of a Rectangle = 2W + 2L
2(X) + 2(X + 15)
2X + 2X + 30
4X + 30
Answer = 4X + 30
Hope this helps! :)
Answer:
28.27 cm/s
Step-by-step explanation:
Though Process:
- The punch glass (call it bowl to have a shape in mind) is in the shape of a hemisphere
- the radius
- Punch is being poured into the bowl
- The height at which the punch is increasing in the bowl is
![\frac{dh}{dt} = 1.5](https://tex.z-dn.net/?f=%5Cfrac%7Bdh%7D%7Bdt%7D%20%3D%201.5)
- the exposed area is a circle, (since the bowl is a hemisphere)
- the radius of this circle can be written as
!['a'](https://tex.z-dn.net/?f=%27a%27)
- what is being asked is the rate of change of the exposed area when the height
- the rate of change of exposed area can be written as
. - since the exposed area is changing with respect to the height of punch. We can use the chain rule:
![\frac{dA}{dt} = \frac{dA}{dh} . \frac{dh}{dt}](https://tex.z-dn.net/?f=%5Cfrac%7BdA%7D%7Bdt%7D%20%3D%20%5Cfrac%7BdA%7D%7Bdh%7D%20.%20%5Cfrac%7Bdh%7D%7Bdt%7D)
- and since
the chain rule above can simplified to
-- we can call this Eq(1)
Solution:
the area of the exposed circle is
![A =\pi a^2](https://tex.z-dn.net/?f=A%20%3D%5Cpi%20a%5E2%20)
the rate of change of this area can be, (using chain rule)
we can call this Eq(2)
what we are really concerned about is how
changes as the punch is being poured into the bowl i.e ![\frac{da}{dh}](https://tex.z-dn.net/?f=%5Cfrac%7Bda%7D%7Bdh%7D)
So we need another formula: Using the property of hemispheres and pythagoras theorem, we can use:
![r = \frac{a^2 + h^2}{2h}](https://tex.z-dn.net/?f=r%20%3D%20%5Cfrac%7Ba%5E2%20%2B%20h%5E2%7D%7B2h%7D)
and rearrage the formula so that a is the subject:
![a^2 = 2rh - h^2](https://tex.z-dn.net/?f=a%5E2%20%3D%202rh%20-%20h%5E2)
now we can derivate a with respect to h to get ![\frac{da}{dh}](https://tex.z-dn.net/?f=%5Cfrac%7Bda%7D%7Bdh%7D)
![2a \frac{da}{dh} = 2r - 2h](https://tex.z-dn.net/?f=2a%20%5Cfrac%7Bda%7D%7Bdh%7D%20%3D%202r%20-%202h)
simplify
![\frac{da}{dh} = \frac{r-h}{a}](https://tex.z-dn.net/?f=%5Cfrac%7Bda%7D%7Bdh%7D%20%3D%20%5Cfrac%7Br-h%7D%7Ba%7D)
we can put this in Eq(1) in place of ![\frac{da}{dh}](https://tex.z-dn.net/?f=%5Cfrac%7Bda%7D%7Bdh%7D)
and since we know ![\frac{dh}{dt} = 1.5](https://tex.z-dn.net/?f=%5Cfrac%7Bdh%7D%7Bdt%7D%20%3D%201.5)
![\frac{da}{dt} = \frac{(r-h)(1.5)}{a}](https://tex.z-dn.net/?f=%5Cfrac%7Bda%7D%7Bdt%7D%20%3D%20%5Cfrac%7B%28r-h%29%281.5%29%7D%7Ba%7D%20)
and now we use substitute this
. in Eq(2)
![\frac{dA}{dt} = 2 \pi a \frac{(r-h)(1.5)}{a}](https://tex.z-dn.net/?f=%5Cfrac%7BdA%7D%7Bdt%7D%20%3D%202%20%5Cpi%20a%20%5Cfrac%7B%28r-h%29%281.5%29%7D%7Ba%7D)
simplify,
![\frac{dA}{dt} = 3 \pi (r-h)](https://tex.z-dn.net/?f=%5Cfrac%7BdA%7D%7Bdt%7D%20%3D%203%20%5Cpi%20%28r-h%29)
This is the rate of change of area, this is being asked in the quesiton!
Finally, we can put our known values:
![r = 5cm](https://tex.z-dn.net/?f=r%20%3D%205cm)
from the question
![\frac{dA}{dt} = 3 \pi (5-2)](https://tex.z-dn.net/?f=%5Cfrac%7BdA%7D%7Bdt%7D%20%3D%203%20%5Cpi%20%285-2%29)
![\frac{dA}{dt} = 9 \pi cm/s// or//\frac{dA}{dt} = 28.27 cm/s](https://tex.z-dn.net/?f=%5Cfrac%7BdA%7D%7Bdt%7D%20%3D%209%20%5Cpi%20cm%2Fs%2F%2F%20or%2F%2F%5Cfrac%7BdA%7D%7Bdt%7D%20%3D%2028.27%20cm%2Fs)
Answer:
849.24 cm²
Step-by-step explanation:
we know it is a cube so to find the surface area of each square you do
12x12=144 and there are 5 sides so 144x5=720
We know sides of the squares are 12 cm so half of that (6) would be the bottom of the triangle
Now using pythagorus you would do a²+b²=c²
15²+6²=c²
225+36=c²
√261=√c²
16.15=c this only half of one of the sides of the pyramid so you would times 16.15 by 8 to equal 129.24
now add 720+129.24=849.24 cm²
Answer:
Probability of choosing green and yellow treat is higher than Probability of choosing an orange and yellow treat by 0.08
Step-by-step explanation:
Given -
Green and yellow gummy treats = 20
Red and yellow gummy treats = 14
Orange and yellow gummy treats = 16
Total gummy treat = 20+14+16 = 50
Probability of choosing green and yellow treat = 20/50 = 0.4
Probability of choosing an orange and yellow treat = 16/50 = 0.32
Probability of choosing green and yellow treat is higher than Probability of choosing an orange and yellow treat by 0.08