Answer:
4i.
Step-by-step explanation:
To find the flux through the square, we use the divergence theorem for the flux. So Flux of F(x,y) = ∫∫divF(x,y).dA
F(x,y) = hxy,x - yi
div(F(x,y)) = dF(x,y)/dx + dF(x,y)dy = dhxy/dx + d(x - yi)/dy = hy - i
So, ∫∫divF(x,y).dA = ∫∫(hy - i).dA
= ∫∫(hy - i).dxdy
= ∫∫hydxdy - ∫∫idxdy
Since we are integrating along the boundary of the square given by −1 ≤ x ≤ 1, −1 ≤ y ≤ 1, then
∫∫divF(x,y).dA = ∫₋₁¹∫₋₁¹hydxdy - ∫₋₁¹∫₋₁¹idxdy
= h∫₋₁¹{y²/2}¹₋₁dx - i∫₋₁¹[y]₋₁¹dx
= h∫₋₁¹{1²/2 - (-1)/2²}dx - i∫₋₁¹[1 - (-1)]dx
= h∫₋₁¹{1/2 - 1)/2}dx - i∫₋₁¹[1 + 1)]dx
= 0 - i∫₋₁¹2dx
= - 2i[x]₋₁¹
= 2i[1 - (-1)]
= 2i[1 + 1]
= 2i(2)
= 4i
It would be 400. Hope this helped. :)
Answer: it will take 5 people 6.4 hours to do the work.
Step-by-step explanation:
The number of hours required to do a job varies inversely as the number of people working. Let h represent the number of hours required to do the job. Let p represent the number of people working. Therefore,
h is inversely proportional to p
Introducing a constant of variation, k, it means that
h = k/p
It takes 8 hours for 4 people to paint the inside of a house. Therefore
8 = k/4
k = 8×4 = 32
The formula becomes
h = 32/p
To determine how many hours it will take 5 people to do the work, we will substitute p = 5 into the formula. It becomes
h = 32/5 = 6.4 hours
Answer:
12.4
Step-by-step explanation:
Answer:
Step-by-step explanation:
The ladder forms a right angle triangle with the building and the ground. The length of the ladder represents the hypotenuse of the right angle triangle. The height, h from the top of the ladder to the base of the house represents the opposite side of the right angle triangle.
The distance from the foot of the ladder to the base of the house represents the adjacent side of the right angle triangle.
To determine the height, h that the ladder reaches, we would apply Pythagoras theorem which is expressed as
Hypotenuse² = opposite side² + adjacent side²
15² = 9² + h²
225 = 81 + h²
h² = 225 - 81 = 144
h = √144 = 12 feet
