PLEASE HELP!!!

A model used for the yield y of an agricultural crop as a function of the nitrogen level n in the soil (measured in appropriate

pychu [463]

The maxima of an equation can be obtained by taking the 1st derivative of the equation then equate it to 0.The value of N that result in best yield is when dy/dn = 0.

Taking the 1st derivative of the equation y=(kn)/(9+n^2) :

By using the quotient rule the form of the equation is:
y = g(n) / h(n)
where:

g(n) = kn ---> g'(n) = k

h(n) = 9 + n^2 ---> h'(n) = 2n 
dy/dn is defined as:
dy/dn = [h(n) * g'(n) - h'(n) * g(n)] / h(n)^2
dy/dn = [(9 + n^2)(k) - (kn)(2n)] / (9 + n^2)^2
dy/dn = (9k + kn^2 - 2kn^2) / (9 + n^2)^2
dy/dn = (9k - kn^2) / (9 + n^2)^2
dy/dn = k(9 - n^2) / (9 + n^2)^2

Equate dy/dn = 0, then solve for n
k(9 - n^2) / (9 + n^2)^2 = 0
k(9 - n^2) = 0
9 - n^2 = 0
n^2 = 9
n = sqrt(9)
n = 3

Answer: The nitrogen level that gives the best yield of agricultural crops is 3 units.

5 0

3 years ago

Homes are often insulated with fiberglass insulation in their walls and ceiling. The thermal conductivity of fiberglass is 0.040

Murljashka [212]

Answer:

2.866 x 10^8 J

Explanation:

Thermal conductivity, K = 0.040 W/m^2 k

Area of the wall, A = 470 m^2

Thickness, d = 17 cm = 0.17 m

difference in temperature, ΔT = 30° C

The rate of heat flow is H.

Time, t = 1 day = 1 x 24 x 60 x 60 second = 86400 second

By use of formula of heat flow

$H=\frac{K A \Delta T}{d}t$

$H=\frac{0.040 \times 470 \times 30}{0.17}\times 86400$

H = 2.866 x 10^8 J

3 0

4 years ago

A ball with a mass of 0.585 kg is initially at rest. It is struck by a second ball having a mass of 0.420 kg , initially moving

Y_Kistochka [10]

Answer:

a) $(v_1)=0.3989m/s$

b) $\theta_1=80.5 \textdegree$

c) $K.E=0.036J$

Explanation:

From the question we are told that:

Initial speed of 1st ball $u_{1}=0 m/s$

Mass of 1st ball $m_1=0.585kg$

Mass of 2nd ball $m_2=0.420kg$

Initial speed of 2nd ball $u_{2}=0.270 m/s$

Final speed of 2nd ball $v_{2}=0.220 m/s$

Angle of collision $\angle=36.9 \textdegree$

a)

Generally the equation for law of conservation is mathematically given by

$m_1u_1+m_2u_2=m_1v_1^2+m_2v_2^2$

The final velocity $v_1$ is given as

$0+(0.420)(0.270)=(0.585)(v_1)^2+(0.420)(0.220)^2$

$(v_1)^2=\frac{(0.420)(0.270)-(0.420)(0.220)^2}{0.585}$

$(v_1)^2=0.1591$

$(v_1)=0.3989m/s$

b)

Generally the equation for law of conservation is mathematically given by

$m_1u_1+m_2u_2=m_1v_1cos\theta_1+m_2\theta_2$

$0+(0.420)(0.270)=(0.585)(1.511)cos\theta_1+(0.420)(0.220)cos36 \textdegree$

$cos\theta_1= \frac{(0.420)(0.270)-(0.420)(0.220)cos36 \textdegree}{(0.585)(0.3989)}$

$cos\theta_1=0.1656$

$\theta_1=80.5 \textdegree$

c)

Generally the equation for kinetic energy is mathematically given by

$K.E=\frac{1}{2} mv^2$

1st Ball

$K.E=\frac{1}{2} (0.585)(0.3989)^2$

$K.E=0.0465J$

2nd ball

$K.E=\frac{1}{2} (0.420)(0.220)^2$

$K.E=0.101J$

Therefore the change in the total kinetic energy of the two balls as a result of the collision is

$0.101-0.0465$

$K.E=0.036J$

3 0

3 years ago

Two campers in a national park hike from their cabin to the same spot on a lake, each taking a different path, as illustrated be

elixir [45]

Answer:

Their displacement is 5 Km from the cabin.

Explanation:

The displacement is define is the shortest distance between two points. It is the shortest distance of a line that joins two points together. It quantifies both the distance and direction of the net or total motion along a straight line from the initial position to the final position of the point trajectory. In this case, the straight line joining the cabin to the stream is line S which is equal to 5 Km

3 0

3 years ago

Who ever gets it I will give Brainly and 20 points

Likurg_2 [28]

What are the options for A,B,C,D? There’s arrows

5 0

3 years ago

Read 2 more answers