Answer:
Barbara's speed in clear weather is
and in the thunderstorm is
.
Step-by-step explanation:
Let
be the speed and
be the time Barbara drives in clear weather, and let
be the speed and
be the time she drives in the thunderstorm.
Barbara drives 22 mph lower in the thunderstorm than in the clear weather; therefore,
(1). ![v_2 = v_1 -22](https://tex.z-dn.net/?f=v_2%20%3D%20v_1%20-22)
Also,
(2).
(3).
,
and
(4). ![t_1+t_2 = 2.25hr](https://tex.z-dn.net/?f=t_1%2Bt_2%20%3D%202.25hr)
From equations (2) and (3) we get:
![t_1 = \dfrac{45}{v_1}](https://tex.z-dn.net/?f=t_1%20%3D%20%5Cdfrac%7B45%7D%7Bv_1%7D)
![t_2 =\dfrac{57}{v_2}](https://tex.z-dn.net/?f=t_2%20%3D%5Cdfrac%7B57%7D%7Bv_2%7D)
putting these in equation (4) we get:
![\dfrac{45}{v_1}+\dfrac{57}{v_2}=2.25](https://tex.z-dn.net/?f=%5Cdfrac%7B45%7D%7Bv_1%7D%2B%5Cdfrac%7B57%7D%7Bv_2%7D%3D2.25)
and substituting for
from equation (1) we get:
![\dfrac{45}{v_1}+\dfrac{57}{v_1-22}=2.25](https://tex.z-dn.net/?f=%5Cdfrac%7B45%7D%7Bv_1%7D%2B%5Cdfrac%7B57%7D%7Bv_1-22%7D%3D2.25)
This equation can be rewritten as
![2.25v_1^2-151.5v_1+990=0](https://tex.z-dn.net/?f=2.25v_1%5E2-151.5v_1%2B990%3D0)
which has solutions
![v_1 = 60](https://tex.z-dn.net/?f=v_1%20%3D%2060)
![v_1 = 7.33](https://tex.z-dn.net/?f=v_1%20%3D%207.33)
We take the first solution
because it gives a positive value for ![v_2:](https://tex.z-dn.net/?f=v_2%3A)
![v_2 = v_1 -22](https://tex.z-dn.net/?f=v_2%20%3D%20v_1%20-22)
![v_2 = 60 -22\\](https://tex.z-dn.net/?f=v_2%20%3D%2060%20-22%5C%5C)
.
Thus, Barbara's speed in clear weather is
and in the thunderstorm is
.
Answer:
Drone = $300
4 Extra Set Of Propellor = 4(25$) = $100
Step-by-step explanation:
Answer:
12 cubes
Step-by-step explanation:
If the total volume of the box is 24 cm³ and the volume of each cube is 1 cm³ then that means that 24 total cubes can fit perfectly inside the box. Since there can only be two layers of cubes then we simply need to divide the total amount of cubes that will fit in the box by 2 to find the number of cubes in each layer...
24 / 2 = 12 cubes
Finally, we can see that each layer within the box will contain 12 cubes
<span>Ishaan is 21, Christopher is 7
No actual question given, but I will assume that the question is "How old are they?". If that's the case, we can create two equations. I'll use I for Ishaan's age and C for Christopher's. I will also assume that there's been some formatting issues here and for some reason, numbers are repeated 3 times without any spaces. So
"Ishaan is 3 times as old as Christopher"
I = 3C
"is also 14 years older than Christopher
I = C + 14
Since both equations are equal to each other, let's set them equal. So
3C = C + 14
2C = 14
C = 7
So Christopher is 7. And we can use the equation I = C + 14 to get Ishaan's age. So
I = C + 14
I = 7 + 14
I = 21</span>
If you are evaluating the answer is -41