The second one is the right answer
Answer:
Step-by-step explanation:
concentration = amount of salt/solution
A) Initial concentration= 90/1000 = 0.09
Q = quantity of salt
Q(0) = 90 kg
Inflow rate = 8 l/min
Outflow rate = 8 l/min
Solution = 1000 L at any time t.
Salt inflow = 0.045 * 8 per minute
= 0.36 kg per minute
This is mixed and drains from the tank.
Outflow =
Thus rate of change of salt
Q'(t) = inflow - outflow =
Separate the variables and integrate
Use the fact that Q(0) = 90
90 = 360-A
A = 270
So
B) Q(t) = 360-270e^-0.004 = 91.07784
C) When t approaches infinity, we get
Q(t) tends to 360
So concentration =360/1000 = 0.36
Answer:
3,409.6 steps
Step-by-step explanation:
Given parameters:
Duration of the walk = 9.00am to 3.00pm
Number of steps walked = 20458 steps
Unknown:
Number of steps per hour =?
To solve this;
Number of steps per hour =
Duration = 9 am to 3pm = 6hrs
Now input the parameters:
Number of steps per hour = = 3,409.6 steps
Total number of steps per hour is 3,409.6 steps/hour.
Answer:
It is better to to buy from At Food Lion
Step-by-step explanation:
At Harris Teeter: 7 picture frames cost $15
Cost per picture frames = Total cost of picture frames / number of picture frames
= $15 / 7
= $2.14 per picture
At Food Lion: 9 picture frames cost $17
Cost per picture frames = Total cost of picture frames / number of picture frames
= $17 / 9
= $1.89 per picture
The cost of pictures frames Amat Food Lion is cheaper than at Harris Teeter
It is better to to buy from At Food Lion