Answer:
Explanation:
whats the answeres two the question do they have a choise for you
Answer:
Change in kinetic energy=-513.652 KJ
Change in potential energy=431.64KJ
Explanation:
We are given that
Mass of an automobile , m=1100 kg
Initial speed, u=110 km/h=![110\times \frac{5}{18}=30.56 m/s](https://tex.z-dn.net/?f=110%5Ctimes%20%5Cfrac%7B5%7D%7B18%7D%3D30.56%20m%2Fs)
Where ![1 km/h=5/18 m/s](https://tex.z-dn.net/?f=1%20km%2Fh%3D5%2F18%20m%2Fs)
Height , ![h_2=40 m](https://tex.z-dn.net/?f=h_2%3D40%20m)
![g=9.81 m/s^2](https://tex.z-dn.net/?f=g%3D9.81%20m%2Fs%5E2)
Final speed, v=0
Change in kinetic energy,![\Delta K.E=\frac{1}{2}m(v^2-u^2)](https://tex.z-dn.net/?f=%5CDelta%20K.E%3D%5Cfrac%7B1%7D%7B2%7Dm%28v%5E2-u%5E2%29)
![\Delta K.E=\frac{1}{2}(1100)(0-(30.56)^2)=-513652.48 J](https://tex.z-dn.net/?f=%5CDelta%20K.E%3D%5Cfrac%7B1%7D%7B2%7D%281100%29%280-%2830.56%29%5E2%29%3D-513652.48%20J)
![\Delta K.E=-\frac{513652.48}{1000}=-513.652 KJ](https://tex.z-dn.net/?f=%5CDelta%20K.E%3D-%5Cfrac%7B513652.48%7D%7B1000%7D%3D-513.652%20KJ)
Where 1 KJ=1000 J
Change in potential energy,![\Delta P.E=mgh(h_2-h_1)](https://tex.z-dn.net/?f=%5CDelta%20P.E%3Dmgh%28h_2-h_1%29)
Initially height, h1=0
Using the formula
![\Delta P.E=1100\times 9.81(40-0)](https://tex.z-dn.net/?f=%5CDelta%20P.E%3D1100%5Ctimes%209.81%2840-0%29)
![\Delta P.E=431640J](https://tex.z-dn.net/?f=%5CDelta%20P.E%3D431640J)
![\Delta P.E=431.64KJ](https://tex.z-dn.net/?f=%5CDelta%20P.E%3D431.64KJ)
Answer: 33.35 minutes
Explanation:
A(t) = A(o) *(.5)^[t/(t1/2)]....equ1
Where
A(t) = geiger count after time t = 100
A(o) = initial geiger count = 400
(t1/2) = the half life of decay
t = time between geiger count = 66.7 minutes
Sub into equ 1
100=400(.5)^[66.7/(t1/2)
Equ becomes
.25= (.5)^[66.7/(t1/2)]
Take log of both sides
Log 0.25 = [66.7/(t1/2)] * log 0.5
66.7/(t1/2) = 2
(t1/2) = (66.7/2 ) = 33.35 minutes
Answer: the correct answer is D
Answer:
474.59 mg/L
Explanation:
Given that
BOD = 30 mg/L
Original BOD = 30 mg/L × dilution factor
Original BOD = 30 mg/L × 10 = 300 mg/L
![L_o = \frac{BOD}{1-e^{-5t}}](https://tex.z-dn.net/?f=L_o%20%3D%20%5Cfrac%7BBOD%7D%7B1-e%5E%7B-5t%7D%7D)
here
is the ultimate BOD ; BOD is the biochemical oxygen demand ; t = 0.20 /day
![L_o = \frac{300}{1-e^{-5(0.20)}}](https://tex.z-dn.net/?f=L_o%20%3D%20%5Cfrac%7B300%7D%7B1-e%5E%7B-5%280.20%29%7D%7D)