<h2>
Dimension for cheap enclose = 32.45 ft x 23.52 ft</h2>
Explanation:
Area of rectangular field, A = 830 ft²
Length = l
Width = w
So we have
l x w = 830

Fencing costs $2 per foot for two opposite sides, and $3 per foot for the other two sides.
Cost for fencing, C = 2 x 2 x w + 3 x 2 x l = 4 w + 6 l

For minimum cost we have derivative is zero

Dimension for cheap enclose = 32.45 ft x 23.52 ft
Answer:
During a lunar eclipse, the Moon turns red because the only sunlight reaching the Moon passes through Earth's atmosphere. The more dust or clouds in Earth's atmosphere during the eclipse, the redder the Moon will appear.
3.5 seconds is 3500 milliseconds.
Answer:
<h2>
3,343.68kJ </h2>
Explanation:
Heat energy used up can be calculated using the formula:
H = mcΔt
m = mass oof the object (in kg) = 20kg
c = specific heat capacity of water = 4179.6J/kg°C
Δt change in temperature = 80-40 = 40°C
H= 20* 4179.6 * 40
H = 3,343,680Joules
H = 3,343.68kJ