What do you mean you need to be more specific
<span>The distance between two objects is increased by three times the oringinal distance. Since they were already separated by one time the original distance,
the additional three times the oringinal distance now puts them four times the original distance apart.
Whether we're talking about the gravitational forces of attraction or
the electrical forces of attraction, either one is inversely proportional
to the square of the distance between the objects.
So changing the distance to four times the original distance causes
the forces to become 1/4</span>² as strong as they were originally.
The forces become 1/16 of their original magnitude.<span>
</span>
When visible light, X rays, gamma rays, or other forms of electromagnetic radiation are shined on certain kinds of matter, electrons are ejected. That phenomenon is known as the photoelectric effect. The photoelectric effect was discovered by German physicist Heinrich Hertz (1857–1894) in 1887. You can imagine the effect as follows: Suppose that a metal plate is attached by two wires to a galvanometer. (A galvanometer is an instrument for measuring the flow of electric current.) If light of the correct color is shined on the metal plate, the galvanometer may register a current. That reading indicates that electrons have been ejected from the metal plate. Those electrons then flow through the external wires and the galvanometer. HOPE THIS HELPED
Answer:
c. expanded polyurethane
Explanation:
Thermal performance of a building fabric is measured in terms of heat loss and is expressed as U-value or R-value. U-value is the rate of heat transferred through a structure divided by the difference in temperature across the structure with a unit of measurement of W/m²K.You can calculate the U-value of a by getting the reciprocal of the sum of thermal resistances , R, making the building material.
If you have the value of R, then U=1/R
Material size R U
plywood 1" 1.25 0.8
Poured concrete 2" 0.99 1.010
Expanded polyurethane 1" 6.5 0.1538
Asbestos shingles 1" 0.03 33.33
The material with lowest U-value is expanded polyurethane
