Answer:
The differential equation is ![\frac{dR}{dt} = -kR](https://tex.z-dn.net/?f=%5Cfrac%7BdR%7D%7Bdt%7D%20%3D%20-kR)
Step-by-step explanation:
Differential equation for the rate of change in radiation level:
Radiation level is R.
Rate of change indicates that the radiation level R varies in function of time t, which mathematically means that we have:
![\frac{dR}{dt}](https://tex.z-dn.net/?f=%5Cfrac%7BdR%7D%7Bdt%7D)
After the reactor is shut down, the radiation from the nitrogen-17 decreases in such a way that the rate of change in the radiation level is directly proportional to the radiation level.
Rate of change is k. Decreases means that k is negative. Proportional to the radiation level of R means that -k multiplies R. So the differential equation is:
![\frac{dR}{dt} = -kR](https://tex.z-dn.net/?f=%5Cfrac%7BdR%7D%7Bdt%7D%20%3D%20-kR)
Answer:
x = 7
Step-by-step explanation:
123 = 17x + 4
123 - 4 = 17x
119 = 17x
119 / 17 = x
7 = x
The correct answer is B. -2x-6
the height of the house is
.
<u>Step-by-step explanation:</u>
Here we have , To estimate the height of a house Katie stood a certain distance from the house and determined that the angle of elevation to the top of the house was 32 degrees. Katie then moved 200 feet closer to the house along a level street and determined the angle of elevation was 42 degrees. We need to find What is the height of the house . Let's find out:
Let y is the unknown height of the house, and x is the unknown number of feet she is standing from the house.
Distance of house from point A( initial point ) = x ft
Distance of house from point B( when she traveled 200 ft towards street = x-200 ft
Now , According to question these scenarios are of right angle triangle as
At point A
⇒ ![Tan32 =\frac{Perpendicular}{Base}= \frac{y}{x}](https://tex.z-dn.net/?f=Tan32%20%3D%5Cfrac%7BPerpendicular%7D%7BBase%7D%3D%20%5Cfrac%7By%7D%7Bx%7D)
⇒ ![Tan32 = \frac{y}{x}](https://tex.z-dn.net/?f=Tan32%20%3D%20%5Cfrac%7By%7D%7Bx%7D)
⇒
..................(1)
Also , At point B
⇒ ![Tan42 = \frac{y}{x-200}](https://tex.z-dn.net/?f=Tan42%20%3D%20%5Cfrac%7By%7D%7Bx-200%7D)
⇒
..............(2)
Equating both equations:
⇒ ![(x-200)(Tan42) = x(Tan32)](https://tex.z-dn.net/?f=%28x-200%29%28Tan42%29%20%3D%20x%28Tan32%29)
⇒ ![x(Tan42-Tan32)=Tan42(200)](https://tex.z-dn.net/?f=x%28Tan42-Tan32%29%3DTan42%28200%29)
⇒ ![x=\frac{Tan42(200)}{(Tan42-Tan32)}](https://tex.z-dn.net/?f=x%3D%5Cfrac%7BTan42%28200%29%7D%7B%28Tan42-Tan32%29%7D)
⇒ ![x=653ft](https://tex.z-dn.net/?f=x%3D653ft)
Putting
in
we get:
⇒
⇒ ![y=653(Tan32 )](https://tex.z-dn.net/?f=y%3D653%28Tan32%20%29)
⇒ ![y=408ft](https://tex.z-dn.net/?f=y%3D408ft)
Therefore , the height of the house is
.
V = 576 pi cm^3
Step-by-step explanation:
The volume of a cylinder is given by
V = pi r^2 h where r is the radius and h is the height
V = pi * (6)^2 * 16
V = pi *36*16
V = 576 pi cm^3