Answer:
400 m^2.
Step-by-step explanation:
The largest area is obtained where the enclosure is a square.
I think that's the right answer because a square is a special form of a rectangle.
So the square would be 20 * 20 = 400 m^2.
Proof:
Let the sides of the rectangle be x and y m long
The area A = xy.
Also the perimeter 2x + 2y = 80
x + y = 40
y = 40 - x.
So substituting for y in A = xy:-
A = x(40 - x)
A = 40x - x^2
For maximum value of A we find the derivative and equate it to 0:
derivative A' = 40 - 2x = 0
2x = 40
x = 20.
So y = 40 - x
= 40 - 20
=20
x and y are the same value so x = y.
Therefore for maximum area the rectangle is a square.
Answer:
b = 43
Since 43 is congruent to b
Answer:
it -1
Step-by-step explanation:
Answer:
Radiant energy is the energy of electromagnetic waves.
Step-by-step explanation:
I
Answer:
Given:-
The length of copper wire (L) = 270 cm
Area of cross-sectional (A) = 0.030 
and specific resistance (ρ) = 
ohm-cm.
Use the formula R=(Specific resistance*L)/A, to calculate the Resistance(R)
then, 
ohm
Simplify:
R = 0.0162 ohm = 
ohm
Therefore, the resistance of copper wire is, Ω
