Answer:
Concrete
Explanation:
The speed at which sound propagates is medium dependent. As one of the forms of mechanical waves, sound requires a material medium for propagation from place to place.
- Sound travels with the least speed in air because air particles are far apart and they are randomized.
- Sound travels with the greatest speed in solids. Concrete is the only solid material given in the choice.
The speed of sound increases from air to liquid and to solid.
Answer:
We would not be able to make our way around the earth's surface, to read, to sculpt or to create technology because we cannot see!
Explanation:
The minimum angular separation that can be distinguished by an eye gives the angular resolution of the eye.
Given that the Angular resolution with infrared radiation is = 
equal to 
This resolution is very much greater than that of the eye 
The angular resolution that our eyes can see is about 
at arms length
Angular resolution of infrared = 
at arms length
We therefore cannot read, sculpt or create technology because we cannot see.
I think answer should be 15 I think you should google it on the internet
Answer:
Option B
3
Explanation:
The two dimensions have the following significant numbers
4.56- 3 significant numbers
5.668- 4 significant figures
When responding, we give area as per the most precise number given hence the smallest (most precise) significant figures in these two numbers is 3. Therefore, the area will be given to 3 significant figures ie
4.56*5.668=25.84608 square meters
Area=25.8 square meters
