This law states that, despite chemical reactions or physical transformations, mass is conserved — that is, it cannot be created or destroyed — within an isolated system
        
             
        
        
        
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
 
        
             
        
        
        
Answer:10842.33m/s
Explanation:
F=qvBsine
V=f/(qBsine)
V=(3.5×10^-2)÷(8.4×10^-4×6.7×10^-3×sin35)
V=10842.33m/s
 
        
             
        
        
        
Two fat black arrows are swimming along together, when they see a single skinny black arrow coming toward them. They are afraid of strangers, and they know that the skinny one must be mean and tough if it's not afraid to travel alone. So they turn to the side and get out of the skinny arrow's way.
 
        
             
        
        
        
It’s frequency is high and microwaves can pass through the atmosphere of the Earth.