Answer:
Heat lost thru doors & windows = (100 - 75 - 5) = 20
20% is the fraction of heat lost thru doors and windows
One wants to obtain the largest savings per unit of cost
roof:
200 / 600 = 1/3
150 / 1000 = .15
40 / 2300 = .017
The largest of these is 1/3 so the most benefit would be obtained by insulating the roof
Since heat loss thru the roof depends on heat loss thru the attic, this is the most cost effective in reducing heat loss
The more the difference in temperature between the ceiling and roof (attic) the more heat will be lost thru the roof, so insulating the roof will decrease the heat loss of the attic
Answer:
a. 77.9 nT
Explanation:
Given;
average value of the electromagnetic wave, E = 0.724 W/m^2
The average value of a Poynting vector is given by;

Therefore, the maximum value of the magnetic field in the wave is 77.9 nT.
The Sun does emit xrays.
You'd have to place your sensor above the Earth's atmosphere because it blocks out nearly all x-rays. This is why we have the Chandra observatory ( http://chandra.harvard.edu/xray_astro/absorption.html )
A. They must have a potential difference
Potential difference is voltage and voltage is basically the thing that causes current to flow
Answer:
a species on which other species in an ecosystem largely depend, such that if it were removed the ecosystem would change drastically. An example is a predator-prey relationship. If there was no more prey the predators may began to fall ill and die and if there was no more predators the prey would eventually over populate
Explanation: