Answer:
i)W = 2500 / T
ii) W = 500 Tons
iii) grad W(10°) = - 25î
iv) The formulation is not practical
Step-by-step explanation:
i) Write an equation describing the use of coal
As use of coal is inversely proportional to the average monthly temperature
if W is use of coal in tons/per month then
W(t) = k / T where k is a constant of proportionality and T is the average temperature in degrees. We have to determine k from given conditions
k = ?? we know that when T = 25° W = 100 tons the by subtitution
W = k/T 100 = k /25 k = 2500 Tons*degree
Then final equation is:
W = 2500 / T
ii) Find the amount of coal when T = 5 degrees
W = 2500 / 5
W = 500 Tons
iii)
The inverse proportionality implies that W will decrease as T increase.
The vector gradient of W function is:
grad W = DW(t)/dt î
grad W = - 2500/T² î
Wich agrees with the fact that W is decreasing.
And when T = 100°
grad W(10°) = - 2500/ 100 î ⇒ grad W(10°) = - 25î
iv) When T = 0 The quantity of coal tends to infinite and the previous formulation is not practical
Answer:
608
Step-by-step explanation:
There are a total of 1,824 drinks since there were 76 cases at 24 drinks a piece. This creates a total number of 24*76 = 1824.
If each student receives 3 then 1824/3 = 608. There were 608 students.
Answer:
Answer: Around 1000 students would buy a school lunch.
Step-by-step explanation:
We know that in one class, 14 students bring lunch from home, and 20 buy lunch in the school. This will be our sample.
In total we have 20 + 14 = 34 students, this will be our 100%.
The percentage of students that bring lunch from home can be estimated as the quotient between the number of students that bring lunch from home and the total number of students, times 100%.
p1 = (14/34)*100% = 41.18%
And the percentage of students that buy lunch at school can be computed in the same way:
p2= (20/34)*100% = 58.82%
Then, out of the 1700 students in middle school, we can estimate that around 58.82% of them will buy lunch in the school.
Then the exact number will be:
N = (58.82%/100%)*1700 = 1000
Around 1000 students would buy a school lunch.
Answer:
The answer I would choose is c
Hope this helped :)
